| 1998-04-01 | @ MON | 1 | W 4-0 | 1-0 | 1 | 31,220 | Francisco Cordova | Carlos Perez | Francisco Cordova | Carlos Perez | | 4 | 0 | 4 |
| 1998-04-02 | @ MON | 2 | W 4-3 | 2-0 | 1 | 6,396 | Jason Schmidt | Dustin Hermanson | Jason Schmidt | Mike Maddux | Rich Loiselle | 8 | 3 | 5 |
| 1998-04-03 | @ NYN | 3 | L 1-2 | 2-1 | 3 | 15,245 | Esteban Loaiza | Rick Reed | Greg McMichael | Chris Peters | | 9 | 5 | 4 |
| 1998-04-04 | @ NYN | 4 | L 6-7 | 2-2 | 5 | 17,633 | Jon Lieber | Dave Mlicki | Turk Wendell | Chris Peters | | 15 | 12 | 3 |
| 1998-04-05 | @ NYN | 5 | L 0-7 | 2-3 | 6 | 18,205 | Jose Silva | Masato Yoshii | Masato Yoshii | Jose Silva | | 15 | 19 | -4 |
| 1998-04-06 | @ NYN | 6 | W 4-2 | 3-3 | 6 | 13,528 | Francisco Cordova | Bobby Jones | Francisco Cordova | Bobby Jones | Rich Loiselle | 19 | 21 | -2 |
| 1998-04-07 | vs ATL | 7 | L 3-11 | 3-4 | 6 | 43,268 | Jason Schmidt | Tom Glavine | Tom Glavine | Jason Schmidt | | 22 | 32 | -10 |
| 1998-04-08 | vs ATL | 8 | W 5-3 | 4-4 | 5 | 11,254 | Esteban Loaiza | Denny Neagle | Esteban Loaiza | Denny Neagle | Rich Loiselle | 27 | 35 | -8 |
| 1998-04-09 | vs ATL | 9 | L 3-4 | 4-5 | 5 | 9,560 | Jon Lieber | Kevin Millwood | Kevin Millwood | Jon Lieber | Mark Wohlers | 30 | 39 | -9 |
| 1998-04-10 | vs FLO | 10 | W 4-1 | 5-5 | 5 | 16,561 | Jose Silva | Brian Meadows | Jose Silva | Brian Meadows | Rich Loiselle | 34 | 40 | -6 |
| 1998-04-11 | vs FLO | 11 | W 7-6 | 6-5 | 5 | 19,920 | Francisco Cordova | Livan Hernandez | Rich Loiselle | Jay Powell | | 41 | 46 | -5 |
| 1998-04-12 | vs FLO | 12 | W 7-3 | 7-5 | 4 | 12,203 | Jason Schmidt | Rafael Medina | Jason Schmidt | Rafael Medina | | 48 | 49 | -1 |
| 1998-04-13 | vs FLO | 13 | L 2-7 | 7-6 | 4 | 10,938 | Esteban Loaiza | Andy Larkin | Andy Larkin | Esteban Loaiza | | 50 | 56 | -6 |
| 1998-04-14 | @ ATL | 14 | L 0-6 | 7-7 | 5 | 31,259 | Jon Lieber | Kevin Millwood | Kevin Millwood | Jon Lieber | | 50 | 62 | -12 |
| 1998-04-15 | @ ATL | 15 | L 0-7 | 7-8 | 6 | 30,381 | Jose Silva | Greg Maddux | Greg Maddux | Jose Silva | | 50 | 69 | -19 |
| 1998-04-16 | @ ATL | 16 | L 1-3 | 7-9 | 6 | 35,760 | Francisco Cordova | John Smoltz | John Smoltz | Francisco Cordova | Mark Wohlers | 51 | 72 | -21 |
| 1998-04-17 | vs SDN | 17 | L 5-7 | 7-10 | 6 | 12,555 | Jason Schmidt | Joey Hamilton | Brian Boehringer | Jeff Tabaka | Trevor Hoffman | 56 | 79 | -23 |
| 1998-04-18 | vs SDN | 18 | L 5-7 | 7-11 | 6 | 14,728 | Esteban Loaiza | Andy Ashby | Dan Miceli | Rich Loiselle | Trevor Hoffman | 61 | 86 | -25 |
| 1998-04-21 | vs SFN | 19 | L 3-6 | 7-12 | 6 | 8,976 | Jon Lieber | Mark Gardner | Mark Gardner | Jon Lieber | | 64 | 92 | -28 |
| 1998-04-22 | vs SFN | 20 | W 5-2 | 8-12 | 6 | 11,367 | Jose Silva | Danny Darwin | Jose Silva | Danny Darwin | Rich Loiselle | 69 | 94 | -25 |
| 1998-04-23 | vs SFN | 21 | W 7-0 | 9-12 | 6 | 9,899 | Francisco Cordova | Shawn Estes | Francisco Cordova | Shawn Estes | | 76 | 94 | -18 |
| 1998-04-24 | @ SDN | 22 | W 4-2 | 10-12 | 5 | 26,413 | Jason Schmidt | Pete Smith | Jason Schmidt | Pete Smith | Ricardo Rincon | 80 | 96 | -16 |
| 1998-04-25 | @ SDN | 23 | L 3-4 | 10-13 | 6 | 53,710 | Esteban Loaiza | Sterling Hitchcock | Carlos Reyes | Javier Martinez | | 83 | 100 | -17 |
| 1998-04-26 | @ SDN | 24 | W 6-0 | 11-13 | 5 | 42,281 | Jon Lieber | Kevin Brown | Jon Lieber | Kevin Brown | | 89 | 100 | -11 |
| 1998-04-27 | @ SFN | 25 | L 5-6 | 11-14 | 6 | 10,127 | Jose Silva | Danny Darwin | Robb Nen | Rich Loiselle | | 94 | 106 | -12 |
| 1998-04-28 | @ SFN | 26 | L 1-2 | 11-15 | 6 | 11,551 | Francisco Cordova | Shawn Estes | Shawn Estes | Francisco Cordova | Robb Nen | 95 | 108 | -13 |
| 1998-04-30 | vs LAN | 27 | L 6-14 | 11-16 | 6 | 9,728 | Jason Schmidt | Ismael Valdez | Brad Clontz | Elmer Dessens | | 101 | 122 | -21 |
| 1998-05-01 | vs LAN | 28 | W 5-4 | 12-16 | 6 | 15,491 | Esteban Loaiza | Darren Dreifort | Jeff Tabaka | Darren Dreifort | Rich Loiselle | 106 | 126 | -20 |
| 1998-05-02 | vs LAN | 29 | L 4-5 | 12-17 | 6 | 22,629 | Jon Lieber | Ramon Martinez | Ramon Martinez | Jon Lieber | Scott Radinsky | 110 | 131 | -21 |
| 1998-05-03 | vs LAN | 30 | L 5-10 | 12-18 | 6 | 18,674 | Jose Silva | Chan Ho Park | Chan Ho Park | Jose Silva | | 115 | 141 | -26 |
| 1998-05-05 | vs SLN | 31 | W 5-2 | 13-18 | 6 | 10,329 | Francisco Cordova | Kent Mercker | Francisco Cordova | Kent Mercker | Rich Loiselle | 120 | 143 | -23 |
| 1998-05-06 | vs SLN | 32 | W 5-0 | 14-18 | 6 | 12,051 | Jason Schmidt | Todd Stottlemyre | Jason Schmidt | Todd Stottlemyre | | 125 | 143 | -18 |
| 1998-05-07 | vs CIN | 33 | W 8-7 | 15-18 | 6 | 8,400 | Esteban Loaiza | David Weathers | Elmer Dessens | Stan Belinda | Rich Loiselle | 133 | 150 | -17 |
| 1998-05-08 | vs CIN | 34 | L 3-5 | 15-19 | 6 | 13,848 | Jon Lieber | Brett Tomko | Stan Belinda | Ricardo Rincon | Jeff Shaw | 136 | 155 | -19 |
| 1998-05-09 | vs CIN | 35 | W 6-1 | 16-19 | 6 | 27,185 | Jose Silva | Scott Winchester | Jose Silva | Scott Winchester | Chris Peters | 142 | 156 | -14 |
| 1998-05-10 | vs CIN | 36 | L 3-4 | 16-20 | 6 | 19,507 | Francisco Cordova | Pete Harnisch | Stan Belinda | Rich Loiselle | | 145 | 160 | -15 |
| 1998-05-11 | vs COL | 37 | W 5-2 | 17-20 | 6 | 9,498 | Jason Schmidt | Kevin Ritz | Jason Schmidt | Kevin Ritz | | 150 | 162 | -12 |
| 1998-05-12 | vs COL | 38 | W 6-0 | 18-20 | 6 | 12,954 | Esteban Loaiza | Jamey Wright | Esteban Loaiza | Jamey Wright | | 156 | 162 | -6 |
| 1998-05-13 | @ HOU | 39 | L 0-1 | 18-21 | 6 | 14,239 | Jon Lieber | Mike Hampton | Mike Hampton | Jon Lieber | Billy Wagner | 156 | 163 | -7 |
| 1998-05-14 | @ HOU | 40 | W 7-2 | 19-21 | 6 | 16,123 | Jose Silva | Pete Schourek | Jose Silva | Pete Schourek | | 163 | 165 | -2 |
| 1998-05-15 | @ ARI | 41 | L 1-6 | 19-22 | 6 | 43,584 | Francisco Cordova | Jeff Suppan | Jeff Suppan | Francisco Cordova | | 164 | 171 | -7 |
| 1998-05-16 | @ ARI | 42 | W 6-3 | 20-22 | 6 | 48,167 | Jason Schmidt | Brian Anderson | Jason Schmidt | Brian Anderson | Rich Loiselle | 170 | 174 | -4 |
| 1998-05-17 | @ ARI | 43 | L 2-8 | 20-23 | 6 | 44,014 | Esteban Loaiza | Andy Benes | Andy Benes | Esteban Loaiza | | 172 | 182 | -10 |
| 1998-05-18 | @ ARI | 44 | L 2-9 | 20-24 | 6 | 41,465 | Jon Lieber | Willie Blair | Willie Blair | Jon Lieber | | 174 | 191 | -17 |
| 1998-05-19 | vs SDN | 45 | W 3-0 | 21-24 | 6 | 10,493 | Jose Silva | Joey Hamilton | Jose Silva | Joey Hamilton | Rich Loiselle | 177 | 191 | -14 |
| 1998-05-20 | vs SDN | 46 | W 5-2 | 22-25 | 6 | 0 | Francisco Cordova | Andy Ashby | Francisco Cordova | Andy Ashby | Rich Loiselle | 182 | 193 | -11 |
| 1998-05-20 | vs SDN | 47 | L 3-8 | 22-25 | 6 | 17,248 | Chris Peters | Sterling Hitchcock | Sterling Hitchcock | Chris Peters | | 185 | 201 | -16 |
| 1998-05-21 | vs SDN | 48 | W 3-2 | 23-25 | 5 | 10,222 | Jason Schmidt | Kevin Brown | Jason Schmidt | Kevin Brown | Ricardo Rincon | 188 | 203 | -15 |
| 1998-05-22 | @ FLO | 49 | L 1-3 | 23-26 | 5 | 22,057 | Esteban Loaiza | Livan Hernandez | Livan Hernandez | Esteban Loaiza | | 189 | 206 | -17 |
| 1998-05-23 | @ FLO | 50 | W 10-4 | 24-26 | 5 | 30,499 | Jon Lieber | Joe Fontenot | Jon Lieber | Joe Fontenot | Ricardo Rincon | 199 | 210 | -11 |
| 1998-05-24 | @ FLO | 51 | L 3-4 | 24-27 | 5 | 16,972 | Jose Silva | Jesus Sanchez | Jay Powell | Jason Christiansen | | 202 | 214 | -12 |
| 1998-05-26 | @ MIL | 52 | L 2-3 | 24-28 | 5 | 12,272 | Francisco Cordova | Scott Karl | Mike Myers | Rich Loiselle | | 204 | 217 | -13 |
| 1998-05-27 | @ MIL | 53 | L 2-3 | 24-29 | 6 | 10,274 | Jason Schmidt | Steve Woodard | Brad Woodall | Ricardo Rincon | | 206 | 220 | -14 |
| 1998-05-29 | vs MON | 54 | L 1-4 | 24-30 | 6 | 17,053 | Jon Lieber | Carlos Perez | Carlos Perez | Jon Lieber | Ugueth Urbina | 207 | 224 | -17 |
| 1998-05-30 | vs MON | 55 | W 8-7 | 25-30 | 6 | 38,149 | Jose Silva | Trey Moore | Jason Christiansen | Ugueth Urbina | | 215 | 231 | -16 |
| 1998-05-31 | vs MON | 56 | W 9-4 | 26-30 | 6 | 24,718 | Francisco Cordova | Miguel Batista | Francisco Cordova | Miguel Batista | | 224 | 235 | -11 |
| 1998-06-01 | vs NYN | 57 | W 4-3 | 27-30 | 5 | 11,274 | Jason Schmidt | Dave Mlicki | Jason Schmidt | Dave Mlicki | Ricardo Rincon | 228 | 238 | -10 |
| 1998-06-02 | vs NYN | 58 | W 5-2 | 28-30 | 5 | 9,040 | Chris Peters | Masato Yoshii | Chris Peters | Brian Bohanon | Ricardo Rincon | 233 | 240 | -7 |
| 1998-06-03 | vs NYN | 59 | W 3-0 | 29-30 | 5 | 17,691 | Jon Lieber | Rick Reed | Jon Lieber | Rick Reed | Jason Christiansen | 236 | 240 | -4 |
| 1998-06-05 | vs MIN | 60 | W 6-1 | 30-30 | 4 | 28,446 | Jose Silva | Mike Morgan | Jose Silva | Mike Morgan | | 242 | 241 | 1 |
| 1998-06-06 | vs MIN | 61 | W 4-3 | 31-30 | 3 | 19,809 | Francisco Cordova | Eric Milton | Esteban Loaiza | Rick Aguilera | | 246 | 244 | 2 |
| 1998-06-07 | vs MIN | 62 | L 2-3 | 31-31 | 3 | 32,773 | Jason Schmidt | Bob Tewksbury | Dan Serafini | Jason Schmidt | Rick Aguilera | 248 | 247 | 1 |
| 1998-06-08 | @ CLE | 63 | L 0-8 | 31-32 | 3 | 43,068 | Chris Peters | Bartolo Colon | Bartolo Colon | Chris Peters | | 248 | 255 | -7 |
| 1998-06-09 | @ CLE | 64 | W 7-4 | 32-32 | 3 | 41,762 | Jon Lieber | Dwight Gooden | Jon Lieber | Alvin Morman | Ricardo Rincon | 255 | 259 | -4 |
| 1998-06-10 | @ CLE | 65 | W 4-3 | 33-32 | 3 | 43,101 | Jose Silva | Charles Nagy | Esteban Loaiza | Jose Mesa | Rich Loiselle | 259 | 262 | -3 |
| 1998-06-12 | vs MIL | 66 | L 2-4 | 33-33 | 4 | 16,851 | Francisco Cordova | Scott Karl | Scott Karl | Francisco Cordova | Bob Wickman | 261 | 266 | -5 |
| 1998-06-13 | vs MIL | 67 | L 1-8 | 33-34 | 4 | 28,945 | Jason Schmidt | Jeff Juden | Jeff Juden | Jason Schmidt | | 262 | 274 | -12 |
| 1998-06-14 | vs MIL | 68 | W 7-2 | 34-34 | 4 | 23,755 | Chris Peters | Steve Woodard | Chris Peters | Steve Woodard | | 269 | 276 | -7 |
| 1998-06-15 | @ PHI | 69 | L 1-2 | 34-35 | 4 | 14,411 | Jon Lieber | Matt Beech | Matt Beech | Jon Lieber | Mark Leiter | 270 | 278 | -8 |
| 1998-06-16 | @ PHI | 70 | L 7-8 | 34-36 | 4 | 24,615 | Jose Silva | Tyler Green | Robert Dodd | Rich Loiselle | | 277 | 286 | -9 |
| 1998-06-17 | @ PHI | 71 | L 1-3 | 34-37 | 4 | 25,694 | Francisco Cordova | Curt Schilling | Curt Schilling | Francisco Cordova | | 278 | 289 | -11 |
| 1998-06-18 | @ MIL | 72 | W 1-0 | 35-37 | 4 | 14,774 | Jason Schmidt | Jeff Juden | Elmer Dessens | Doug Jones | Ricardo Rincon | 279 | 289 | -10 |
| 1998-06-19 | @ MIL | 73 | L 1-2 | 35-38 | 5 | 20,935 | Chris Peters | Steve Woodard | Steve Woodard | Chris Peters | Bob Wickman | 280 | 291 | -11 |
| 1998-06-20 | @ MIL | 74 | W 4-2 | 36-38 | 5 | 28,556 | Jon Lieber | Cal Eldred | Jon Lieber | Cal Eldred | Ricardo Rincon | 284 | 293 | -9 |
| 1998-06-21 | @ MIL | 75 | W 8-7 | 37-38 | 5 | 22,338 | Esteban Loaiza | Jeff Juden | Esteban Loaiza | Jeff Juden | Ricardo Rincon | 292 | 300 | -8 |
| 1998-06-22 | vs CHA | 76 | L 4-5 | 37-39 | 5 | 21,531 | Francisco Cordova | Tom Fordham | Carlos Castillo | Elmer Dessens | Matt Karchner | 296 | 305 | -9 |
| 1998-06-23 | vs CHA | 77 | L 4-5 | 37-40 | 5 | 20,310 | Jason Schmidt | Mike Sirotka | Mike Sirotka | Jason Schmidt | Matt Karchner | 300 | 310 | -10 |
| 1998-06-24 | @ KCA | 78 | W 10-3 | 38-40 | 5 | 18,007 | Chris Peters | Glendon Rusch | Chris Peters | Glendon Rusch | | 310 | 313 | -3 |
| 1998-06-25 | @ KCA | 79 | L 1-6 | 38-41 | 5 | 22,504 | Jon Lieber | Tim Belcher | Tim Belcher | Jon Lieber | | 311 | 319 | -8 |
| 1998-06-26 | @ LAN | 80 | L 2-5 | 38-42 | 5 | 52,934 | Esteban Loaiza | Chan Ho Park | Chan Ho Park | Esteban Loaiza | Antonio Osuna | 313 | 324 | -11 |
| 1998-06-27 | @ LAN | 81 | L 0-2 | 38-43 | 5 | 37,821 | Francisco Cordova | Ismael Valdez | Ismael Valdez | Francisco Cordova | | 313 | 326 | -13 |
| 1998-06-28 | @ LAN | 82 | W 6-4 | 39-43 | 5 | 38,865 | Jason Schmidt | Dave Mlicki | Mike Williams | Scott Radinsky | Rich Loiselle | 319 | 330 | -11 |
| 1998-06-30 | vs DET | 83 | L 0-3 | 39-44 | 5 | 11,760 | Jon Lieber | Brian Moehler | Brian Moehler | Jon Lieber | | 319 | 333 | -14 |
| 1998-07-01 | vs DET | 84 | L 1-9 | 39-45 | 5 | 18,957 | Chris Peters | Seth Greisinger | Seth Greisinger | Chris Peters | | 320 | 342 | -22 |
| 1998-07-02 | vs DET | 85 | W 5-2 | 40-45 | 5 | 34,594 | Esteban Loaiza | Brian Powell | Esteban Loaiza | Brian Powell | Rich Loiselle | 325 | 344 | -19 |
| 1998-07-03 | @ CHN | 86 | L 9-12 | 40-46 | 5 | 40,420 | Francisco Cordova | Kevin Tapani | Kevin Tapani | Francisco Cordova | Rod Beck | 334 | 356 | -22 |
| 1998-07-04 | @ CHN | 87 | L 4-5 | 40-47 | 5 | 37,780 | Jason Schmidt | Geremi Gonzalez | Marc Pisciotta | Jason Schmidt | Rod Beck | 338 | 361 | -23 |
| 1998-07-05 | @ CHN | 88 | L 6-7 | 40-48 | 5 | 38,742 | Jon Lieber | Mark Clark | Dave Stevens | Rich Loiselle | Rod Beck | 344 | 368 | -24 |
| 1998-07-10 | vs PHI | 89 | L 6-7 | 40-49 | 5 | 18,665 | Francisco Cordova | Curt Schilling | Curt Schilling | Francisco Cordova | | 350 | 375 | -25 |
| 1998-07-11 | vs PHI | 90 | L 0-1 | 40-50 | 6 | 30,084 | Jason Schmidt | Mark Portugal | Mark Portugal | Rich Loiselle | Mark Leiter | 350 | 376 | -26 |
| 1998-07-12 | vs PHI | 91 | L 4-10 | 40-51 | 6 | 34,144 | Esteban Loaiza | Carlton Loewer | Carlton Loewer | Esteban Loaiza | | 354 | 386 | -32 |
| 1998-07-13 | vs CHN | 92 | W 6-2 | 41-51 | 6 | 11,772 | Jon Lieber | Geremi Gonzalez | Jon Lieber | Geremi Gonzalez | | 360 | 388 | -28 |
| 1998-07-14 | vs CHN | 93 | L 4-7 | 41-52 | 6 | 13,405 | Chris Peters | Kevin Tapani | Kevin Tapani | Chris Peters | Rod Beck | 364 | 395 | -31 |
| 1998-07-15 | vs CHN | 94 | W 3-0 | 42-52 | 6 | 28,655 | Francisco Cordova | Kerry Wood | Francisco Cordova | Kerry Wood | Ricardo Rincon | 367 | 395 | -28 |
| 1998-07-16 | @ MON | 95 | L 5-10 | 42-53 | 6 | 8,558 | Jason Schmidt | Carl Pavano | Carl Pavano | Jason Schmidt | Mike Maddux | 372 | 405 | -33 |
| 1998-07-17 | @ MON | 96 | W 5-1 | 43-53 | 6 | 9,380 | Mike Williams | Javier Vazquez | Mike Williams | Javier Vazquez | Jason Christiansen | 377 | 406 | -29 |
| 1998-07-18 | @ MON | 97 | W 5-2 | 44-53 | 6 | 11,499 | Jon Lieber | Shawn Boskie | Jon Lieber | Shawn Boskie | | 382 | 408 | -26 |
| 1998-07-19 | @ MON | 98 | W 6-1 | 45-53 | 6 | 17,558 | Chris Peters | Dustin Hermanson | Chris Peters | Dustin Hermanson | | 388 | 409 | -21 |
| 1998-07-20 | @ NYN | 99 | W 3-1 | 46-53 | 5 | 18,088 | Francisco Cordova | Masato Yoshii | Francisco Cordova | Masato Yoshii | Ricardo Rincon | 391 | 410 | -19 |
| 1998-07-21 | @ NYN | 100 | L 0-4 | 46-54 | 5 | 22,844 | Jason Schmidt | Rick Reed | Rick Reed | Jason Schmidt | | 391 | 414 | -23 |
| 1998-07-22 | vs FLO | 101 | W 6-4 | 47-54 | 5 | 13,544 | Todd Van Poppel | Ryan Dempster | Todd Van Poppel | Ryan Dempster | Jason Christiansen | 397 | 418 | -21 |
| 1998-07-23 | vs FLO | 102 | W 9-1 | 48-54 | 5 | 11,374 | Jon Lieber | Brian Meadows | Jon Lieber | Brian Meadows | | 406 | 419 | -13 |
| 1998-07-24 | vs ATL | 103 | L 0-3 | 48-55 | 5 | 24,776 | Chris Peters | John Smoltz | John Smoltz | Chris Peters | | 406 | 422 | -16 |
| 1998-07-25 | vs ATL | 104 | W 4-1 | 49-55 | 4 | 41,568 | Francisco Cordova | Denny Neagle | Francisco Cordova | Denny Neagle | Jason Christiansen | 410 | 423 | -13 |
| 1998-07-26 | vs ATL | 105 | L 1-2 | 49-56 | 5 | 34,925 | Jason Schmidt | Greg Maddux | Greg Maddux | Jason Schmidt | Kerry Ligtenberg | 411 | 425 | -14 |
| 1998-07-27 | @ COL | 106 | L 7-8 | 49-57 | 5 | 46,024 | Todd Van Poppel | Mark Brownson | Curt Leskanic | Jeff McCurry | | 418 | 433 | -15 |
| 1998-07-28 | @ COL | 107 | L 6-12 | 49-58 | 5 | 46,856 | Jon Lieber | Pedro Astacio | Pedro Astacio | Jon Lieber | | 424 | 445 | -21 |
| 1998-07-29 | @ COL | 108 | W 12-1 | 50-58 | 4 | 47,411 | Chris Peters | Darryl Kile | Chris Peters | Darryl Kile | | 436 | 446 | -10 |
| 1998-07-31 | vs HOU | 109 | L 4-7 | 50-59 | 5 | 32,476 | Francisco Cordova | Mike Hampton | Mike Hampton | Francisco Cordova | Doug Henry | 440 | 453 | -13 |
| 1998-08-01 | vs HOU | 110 | L 1-2 | 50-60 | 5 | 19,783 | Jason Schmidt | Jose Lima | Jose Lima | Mike Williams | | 441 | 455 | -14 |
| 1998-08-02 | vs HOU | 111 | L 2-6 | 50-61 | 5 | 21,201 | Todd Van Poppel | Randy Johnson | Randy Johnson | Jason Christiansen | Scott Elarton | 443 | 461 | -18 |
| 1998-08-03 | vs COL | 112 | L 2-7 | 50-62 | 6 | 11,204 | Jon Lieber | Bobby Jones | Bobby Jones | Jon Lieber | | 445 | 468 | -23 |
| 1998-08-04 | vs COL | 113 | W 13-5 | 51-62 | 5 | 15,784 | Chris Peters | Darryl Kile | Jason Christiansen | Darryl Kile | | 458 | 473 | -15 |
| 1998-08-05 | vs COL | 114 | L 2-6 | 51-63 | 6 | 12,862 | Francisco Cordova | Jamey Wright | Jamey Wright | Francisco Cordova | | 460 | 479 | -19 |
| 1998-08-06 | vs COL | 115 | L 1-5 | 51-64 | 6 | 14,060 | Jason Schmidt | John Thomson | John Thomson | Jason Schmidt | | 461 | 484 | -23 |
| 1998-08-07 | @ LAN | 116 | L 1-3 | 51-65 | 6 | 41,676 | Todd Van Poppel | Brian Bohanon | Brian Bohanon | Todd Van Poppel | Jeff Shaw | 462 | 487 | -25 |
| 1998-08-08 | @ LAN | 117 | L 1-2 | 51-66 | 6 | 45,187 | Jon Lieber | Dave Mlicki | Antonio Osuna | Jason Christiansen | | 463 | 489 | -26 |
| 1998-08-09 | @ LAN | 118 | W 2-1 | 52-66 | 6 | 43,227 | Chris Peters | Chan Ho Park | Chris Peters | Chan Ho Park | Ricardo Rincon | 465 | 490 | -25 |
| 1998-08-11 | @ CIN | 119 | W 7-0 | 53-66 | 6 | 16,399 | Francisco Cordova | Brett Tomko | Francisco Cordova | Brett Tomko | | 472 | 490 | -18 |
| 1998-08-12 | @ CIN | 120 | W 5-4 | 54-66 | 5 | 16,946 | Jason Schmidt | Mike Remlinger | Jason Schmidt | Mike Remlinger | Ricardo Rincon | 477 | 494 | -17 |
| 1998-08-13 | @ CIN | 121 | W 9-6 | 55-66 | 5 | 16,002 | Todd Van Poppel | Pete Harnisch | Jeff McCurry | Pete Harnisch | Ricardo Rincon | 486 | 500 | -14 |
| 1998-08-14 | @ SLN | 122 | L 5-10 | 55-67 | 5 | 47,836 | Jon Lieber | Donovan Osborne | Donovan Osborne | Jon Lieber | | 491 | 510 | -19 |
| 1998-08-15 | @ SLN | 123 | L 7-8 | 55-68 | 6 | 46,817 | Chris Peters | Darren Oliver | Lance Painter | Jeff McCurry | | 498 | 518 | -20 |
| 1998-08-16 | @ SLN | 124 | W 4-1 | 56-68 | 6 | 46,904 | Francisco Cordova | Matt Morris | Francisco Cordova | Matt Morris | Jon Lieber | 502 | 519 | -17 |
| 1998-08-18 | vs LAN | 125 | W 6-4 | 57-68 | 5 | 12,730 | Jason Schmidt | Carlos Perez | Jason Schmidt | Carlos Perez | Rich Loiselle | 508 | 523 | -15 |
| 1998-08-19 | vs LAN | 126 | W 6-5 | 58-68 | 5 | 27,259 | Todd Van Poppel | Brian Bohanon | Mike Williams | Brian Bohanon | Jason Christiansen | 514 | 528 | -14 |
| 1998-08-20 | vs CIN | 127 | W 6-5 | 59-68 | 5 | 13,137 | Jon Lieber | Dennys Reyes | Jason Christiansen | Danny Graves | | 520 | 533 | -13 |
| 1998-08-21 | vs CIN | 128 | W 14-2 | 60-68 | 5 | 17,007 | Chris Peters | Brett Tomko | Chris Peters | Brett Tomko | | 534 | 535 | -1 |
| 1998-08-22 | vs SLN | 129 | W 14-4 | 61-68 | 5 | 45,082 | Francisco Cordova | Bobby Witt | Francisco Cordova | Bobby Witt | | 548 | 539 | 9 |
| 1998-08-23 | vs SLN | 130 | W 4-3 | 62-68 | 4 | 42,134 | Jason Schmidt | Kent Mercker | Jason Schmidt | Kent Mercker | Jason Christiansen | 552 | 542 | 10 |
| 1998-08-24 | vs SLN | 131 | W 5-5 | 63-68 | 3 | 28,435 | Todd Van Poppel | Kent Bottenfield | | | | 557 | 547 | 10 |
| 1998-08-25 | @ ARI | 132 | W 9-6 | 64-68 | 3 | 38,960 | Sean Lawrence | Clint Sodowsky | Sean Lawrence | Clint Sodowsky | Rich Loiselle | 566 | 553 | 13 |
| 1998-08-26 | @ ARI | 133 | W 4-3 | 65-68 | 3 | 39,906 | Chris Peters | Omar Daal | Jeff Tabaka | Omar Daal | Rich Loiselle | 570 | 556 | 14 |
| 1998-08-28 | @ HOU | 134 | L 0-2 | 65-69 | 3 | 40,709 | Francisco Cordova | Randy Johnson | Randy Johnson | Francisco Cordova | | 570 | 558 | 12 |
| 1998-08-29 | @ HOU | 135 | L 3-6 | 65-70 | 3 | 41,762 | Jason Schmidt | Jose Lima | Jose Lima | Jason Schmidt | Jay Powell | 573 | 564 | 9 |
| 1998-08-30 | @ HOU | 136 | L 4-11 | 65-71 | 3 | 25,342 | Sean Lawrence | Shane Reynolds | Shane Reynolds | Jeff McCurry | | 577 | 575 | 2 |
| 1998-09-01 | vs ARI | 137 | L 3-4 | 65-72 | 4 | 11,427 | Chris Peters | Omar Daal | Omar Daal | Chris Peters | Gregg Olson | 580 | 579 | 1 |
| 1998-09-02 | vs ARI | 138 | L 1-2 | 65-73 | 4 | 12,010 | Elmer Dessens | Andy Benes | Aaron Small | Jeff Tabaka | Gregg Olson | 581 | 581 | 0 |
| 1998-09-03 | vs ARI | 139 | L 0-1 | 65-74 | 5 | 8,610 | Francisco Cordova | Brian Anderson | Brian Anderson | Francisco Cordova | | 581 | 582 | -1 |
| 1998-09-04 | vs CHN | 140 | L 2-5 | 65-75 | 6 | 36,510 | Jason Schmidt | Mark Clark | Matt Karchner | Mike Williams | Rod Beck | 583 | 587 | -4 |
| 1998-09-05 | vs CHN | 141 | L 4-8 | 65-76 | 6 | 37,711 | Sean Lawrence | Kevin Tapani | Kevin Tapani | Sean Lawrence | Rod Beck | 587 | 595 | -8 |
| 1998-09-06 | vs CHN | 142 | W 4-3 | 66-76 | 5 | 22,209 | Chris Peters | Terry Mulholland | Rich Loiselle | Dave Stevens | | 591 | 598 | -7 |
| 1998-09-07 | vs MIL | 143 | L 3-6 | 66-77 | 5 | 12,830 | Elmer Dessens | Rafael Roque | Rafael Roque | Elmer Dessens | Bob Wickman | 594 | 604 | -10 |
| 1998-09-08 | vs MIL | 144 | W 8-7 | 67-77 | 5 | 7,171 | Francisco Cordova | Brad Woodall | Mike Williams | Eric Plunk | Rich Loiselle | 602 | 611 | -9 |
| 1998-09-09 | @ CHN | 145 | L 2-4 | 67-78 | 5 | 34,857 | Jason Schmidt | Mark Clark | Mark Clark | Jason Schmidt | Rod Beck | 604 | 615 | -11 |
| 1998-09-10 | @ CHN | 146 | L 2-5 | 67-79 | 5 | 38,722 | Jose Silva | Kevin Tapani | Kevin Tapani | Jose Silva | Rod Beck | 606 | 620 | -14 |
| 1998-09-11 | @ PHI | 147 | W 6-1 | 68-79 | 5 | 16,597 | Chris Peters | Carlton Loewer | Chris Peters | Carlton Loewer | | 612 | 621 | -9 |
| 1998-09-12 | @ PHI | 148 | L 4-13 | 68-80 | 6 | 19,329 | Elmer Dessens | Mark Portugal | Mark Portugal | Elmer Dessens | | 616 | 634 | -18 |
| 1998-09-13 | @ PHI | 149 | L 1-4 | 68-81 | 6 | 19,662 | Francisco Cordova | Paul Byrd | Paul Byrd | Francisco Cordova | Mark Leiter | 617 | 638 | -21 |
| 1998-09-14 | @ SLN | 150 | L 3-7 | 68-82 | 6 | 42,265 | Jason Schmidt | Jose Jimenez | Jose Jimenez | Jason Schmidt | | 620 | 645 | -25 |
| 1998-09-15 | @ SLN | 151 | W 8-6 | 69-83 | 6 | 0 | Jon Lieber | Donovan Osborne | Sean Lawrence | Donovan Osborne | Rich Loiselle | 628 | 651 | -23 |
| 1998-09-15 | @ SLN | 152 | L 3-9 | 69-83 | 6 | 41,271 | Jose Silva | Manny Aybar | Manny Aybar | Jose Silva | Juan Acevedo | 631 | 660 | -29 |
| 1998-09-16 | @ SLN | 153 | L 0-4 | 69-84 | 6 | 39,758 | Chris Peters | Matt Morris | Matt Morris | Todd Van Poppel | | 631 | 664 | -33 |
| 1998-09-18 | vs HOU | 154 | L 2-5 | 69-85 | 6 | 16,937 | Elmer Dessens | Randy Johnson | Randy Johnson | Elmer Dessens | Jay Powell | 633 | 669 | -36 |
| 1998-09-19 | vs HOU | 155 | W 7-1 | 70-85 | 6 | 20,670 | Francisco Cordova | Jose Lima | Francisco Cordova | Jose Lima | | 640 | 670 | -30 |
| 1998-09-20 | vs HOU | 156 | L 0-2 | 70-86 | 6 | 23,657 | Jason Schmidt | Shane Reynolds | Shane Reynolds | Jason Schmidt | Billy Wagner | 640 | 672 | -32 |
| 1998-09-21 | @ SFN | 157 | L 1-8 | 70-87 | 6 | 15,695 | Jose Silva | Orel Hershiser | Orel Hershiser | Jose Silva | | 641 | 680 | -39 |
| 1998-09-22 | @ SFN | 158 | L 2-14 | 70-88 | 6 | 16,228 | Jon Lieber | Kirk Rueter | Kirk Rueter | Jon Lieber | | 643 | 694 | -51 |
| 1998-09-23 | @ SFN | 159 | L 1-4 | 70-89 | 6 | 13,915 | Chris Peters | Mark Gardner | Mark Gardner | Chris Peters | Robb Nen | 644 | 698 | -54 |
| 1998-09-24 | @ SFN | 160 | L 2-6 | 70-90 | 6 | 16,754 | Elmer Dessens | Russ Ortiz | Russ Ortiz | Elmer Dessens | | 646 | 704 | -58 |
| 1998-09-25 | @ CIN | 161 | L 1-4 | 70-91 | 6 | 17,429 | Francisco Cordova | Jason Bere | Jason Bere | Francisco Cordova | Danny Graves | 647 | 708 | -61 |
| 1998-09-26 | @ CIN | 162 | L 2-6 | 70-92 | 6 | 19,391 | Jason Schmidt | Pete Harnisch | Pete Harnisch | Jason Schmidt | Gabe White | 649 | 714 | -65 |
| 1998-09-27 | @ CIN | 163 | L 1-4 | 70-93 | 6 | 19,360 | Jose Silva | Brett Tomko | Brett Tomko | Jose Silva | | 650 | 718 | -68 |