| 1998-03-31 | vs DET | 1 | L 6-11 | 0-1 | 4 | 45,369 | Wilson Alvarez | Justin Thompson | Justin Thompson | Wilson Alvarez | | 6 | 11 | -5 |
| 1998-04-01 | vs DET | 2 | W 11-8 | 1-1 | 4 | 30,109 | Rolando Arrojo | Brian Moehler | Rolando Arrojo | Brian Moehler | | 17 | 19 | -2 |
| 1998-04-02 | vs DET | 3 | W 7-1 | 2-1 | 3 | 28,261 | Tony Saunders | Tim Worrell | Esteban Yan | Tim Worrell | | 24 | 20 | 4 |
| 1998-04-03 | vs CHA | 4 | L 4-10 | 2-2 | 3 | 31,816 | Rick Gorecki | James Baldwin | James Baldwin | Rick Gorecki | | 28 | 30 | -2 |
| 1998-04-04 | vs CHA | 5 | W 8-2 | 3-2 | 2 | 36,599 | Dennis Springer | Scott Eyre | Dennis Springer | Scott Eyre | | 36 | 32 | 4 |
| 1998-04-05 | vs CHA | 6 | W 5-0 | 4-2 | 2 | 33,733 | Wilson Alvarez | Jason Bere | Wilson Alvarez | Jason Bere | | 41 | 32 | 9 |
| 1998-04-07 | @ DET | 7 | L 1-3 | 4-3 | 2 | 45,768 | Rolando Arrojo | Brian Moehler | Bryce Florie | Rolando Arrojo | Todd Jones | 42 | 35 | 7 |
| 1998-04-10 | @ CHA | 8 | L 0-3 | 4-4 | 3 | 13,563 | Tony Saunders | Mike Sirotka | Mike Sirotka | Tony Saunders | Matt Karchner | 42 | 38 | 4 |
| 1998-04-11 | @ CHA | 9 | W 5-1 | 5-4 | 3 | 17,332 | Rick Gorecki | Jason Bere | Rick Gorecki | Jason Bere | | 47 | 39 | 8 |
| 1998-04-12 | @ CHA | 10 | W 4-1 | 6-4 | 3 | 14,004 | Wilson Alvarez | Jaime Navarro | Wilson Alvarez | Jaime Navarro | Roberto Hernandez | 51 | 40 | 11 |
| 1998-04-13 | vs MIN | 11 | W 13-12 | 7-4 | 2 | 31,969 | Rolando Arrojo | LaTroy Hawkins | Esteban Yan | Mike Trombley | | 64 | 52 | 12 |
| 1998-04-14 | vs MIN | 12 | L 2-8 | 7-5 | 4 | 34,337 | Dennis Springer | Brad Radke | Brad Radke | Dennis Springer | | 66 | 60 | 6 |
| 1998-04-16 | @ ANA | 13 | W 6-5 | 8-5 | 4 | 22,906 | Tony Saunders | Jack McDowell | Tony Saunders | Mike Holtz | Roberto Hernandez | 72 | 65 | 7 |
| 1998-04-17 | @ ANA | 14 | L 0-5 | 8-6 | 4 | 31,516 | Rick Gorecki | Chuck Finley | Chuck Finley | Rick Gorecki | | 72 | 70 | 2 |
| 1998-04-18 | @ ANA | 15 | W 8-1 | 9-6 | 4 | 37,878 | Wilson Alvarez | Jason Dickson | Wilson Alvarez | Jason Dickson | | 80 | 71 | 9 |
| 1998-04-19 | @ ANA | 16 | W 6-0 | 10-6 | 4 | 34,580 | Rolando Arrojo | Allen Watson | Rolando Arrojo | Allen Watson | | 86 | 71 | 15 |
| 1998-04-21 | @ TEX | 17 | L 0-4 | 10-7 | 4 | 26,776 | Dennis Springer | Aaron Sele | Aaron Sele | Dennis Springer | | 86 | 75 | 11 |
| 1998-04-22 | @ TEX | 18 | L 2-7 | 10-8 | 4 | 30,770 | Tony Saunders | Rick Helling | Rick Helling | Tony Saunders | | 88 | 82 | 6 |
| 1998-04-23 | @ TEX | 19 | W 12-5 | 11-8 | 4 | 33,319 | Jason Johnson | Darren Oliver | Jason Johnson | Darren Oliver | | 100 | 87 | 13 |
| 1998-04-24 | vs ANA | 20 | L 3-10 | 11-9 | 4 | 27,767 | Wilson Alvarez | Allen Watson | Allen Watson | Wilson Alvarez | | 103 | 97 | 6 |
| 1998-04-25 | vs ANA | 21 | L 1-7 | 11-10 | 4 | 33,395 | Rolando Arrojo | Ken Hill | Ken Hill | Rolando Arrojo | | 104 | 104 | 0 |
| 1998-04-26 | vs ANA | 22 | L 1-2 | 11-11 | 4 | 26,882 | Dennis Springer | Jack McDowell | Omar Olivares | Dennis Springer | Troy Percival | 105 | 106 | -1 |
| 1998-04-27 | vs OAK | 23 | L 6-7 | 11-12 | 4 | 25,484 | Tony Saunders | Mike Oquist | T.J. Mathews | Roberto Hernandez | Billy Taylor | 111 | 113 | -2 |
| 1998-04-28 | vs OAK | 24 | L 3-4 | 11-13 | 4 | 25,138 | Jason Johnson | Dave Telgheder | Aaron Small | Jason Johnson | Billy Taylor | 114 | 117 | -3 |
| 1998-04-29 | @ MIN | 25 | L 0-2 | 11-14 | 4 | 8,964 | Wilson Alvarez | Bob Tewksbury | Bob Tewksbury | Wilson Alvarez | Rick Aguilera | 114 | 119 | -5 |
| 1998-04-30 | @ MIN | 26 | W 2-0 | 12-14 | 4 | 8,860 | Rolando Arrojo | LaTroy Hawkins | Rolando Arrojo | LaTroy Hawkins | | 116 | 119 | -3 |
| 1998-05-01 | @ CLE | 27 | L 5-7 | 12-15 | 4 | 42,712 | Dennis Springer | Bartolo Colon | Bartolo Colon | Dennis Springer | Michael Jackson | 121 | 126 | -5 |
| 1998-05-02 | @ CLE | 28 | L 1-5 | 12-16 | 4 | 42,525 | Tony Saunders | Chad Ogea | Chad Ogea | Tony Saunders | | 122 | 131 | -9 |
| 1998-05-03 | @ CLE | 29 | L 8-10 | 12-17 | 4 | 42,597 | Jason Johnson | Charles Nagy | Jose Mesa | Roberto Hernandez | | 130 | 141 | -11 |
| 1998-05-05 | @ KCA | 30 | L 2-4 | 12-18 | 5 | 12,096 | Wilson Alvarez | Hipolito Pichardo | Hipolito Pichardo | Wilson Alvarez | Jeff Montgomery | 132 | 145 | -13 |
| 1998-05-06 | @ KCA | 31 | W 5-0 | 13-18 | 5 | 11,401 | Rolando Arrojo | Glendon Rusch | Rolando Arrojo | Glendon Rusch | | 137 | 145 | -8 |
| 1998-05-08 | vs BAL | 32 | L 2-8 | 13-19 | 5 | 35,355 | Tony Saunders | Doug Drabek | Arthur Rhodes | Albie Lopez | | 139 | 153 | -14 |
| 1998-05-09 | vs BAL | 33 | L 0-7 | 13-20 | 5 | 42,486 | Dennis Springer | Mike Mussina | Mike Mussina | Dennis Springer | | 139 | 160 | -21 |
| 1998-05-10 | vs BAL | 34 | W 4-3 | 14-20 | 5 | 34,123 | Wilson Alvarez | Jimmy Key | Esteban Yan | Alan Mills | Roberto Hernandez | 143 | 163 | -20 |
| 1998-05-11 | vs CLE | 35 | W 4-2 | 15-20 | 5 | 30,334 | Rolando Arrojo | Dave Burba | Rolando Arrojo | Dave Burba | Roberto Hernandez | 147 | 165 | -18 |
| 1998-05-12 | vs CLE | 36 | W 6-5 | 16-20 | 5 | 30,194 | Jason Johnson | Bartolo Colon | Julio Santana | Michael Jackson | | 153 | 170 | -17 |
| 1998-05-13 | vs KCA | 37 | L 0-4 | 16-21 | 5 | 25,224 | Tony Saunders | Pat Rapp | Pat Rapp | Tony Saunders | | 153 | 174 | -21 |
| 1998-05-14 | vs KCA | 38 | L 2-10 | 16-22 | 5 | 24,296 | Dennis Springer | Tim Belcher | Tim Belcher | Dennis Springer | | 155 | 184 | -29 |
| 1998-05-15 | @ BAL | 39 | W 4-1 | 17-22 | 5 | 47,421 | Wilson Alvarez | Jimmy Key | Wilson Alvarez | Jimmy Key | Roberto Hernandez | 159 | 185 | -26 |
| 1998-05-16 | @ BAL | 40 | W 5-2 | 18-22 | 5 | 47,538 | Rolando Arrojo | Scott Erickson | Rolando Arrojo | Scott Erickson | Roberto Hernandez | 164 | 187 | -23 |
| 1998-05-17 | @ BAL | 41 | W 7-3 | 19-22 | 5 | 47,628 | Jason Johnson | Scott Kamieniecki | Jim Mecir | Alan Mills | | 171 | 190 | -19 |
| 1998-05-18 | @ BAL | 42 | W 6-3 | 20-22 | 3 | 45,033 | Tony Saunders | Doug Drabek | Albie Lopez | Doug Drabek | Roberto Hernandez | 177 | 193 | -16 |
| 1998-05-19 | @ TOR | 43 | L 1-3 | 20-23 | 4 | 25,662 | Dennis Springer | Woody Williams | Woody Williams | Dennis Springer | Randy Myers | 178 | 196 | -18 |
| 1998-05-20 | @ TOR | 44 | L 1-9 | 20-24 | 4 | 26,107 | Wilson Alvarez | Pat Hentgen | Pat Hentgen | Wilson Alvarez | | 179 | 205 | -26 |
| 1998-05-21 | @ TOR | 45 | L 1-6 | 20-25 | 4 | 30,108 | Rolando Arrojo | Juan Guzman | Juan Guzman | Rolando Arrojo | | 180 | 211 | -31 |
| 1998-05-22 | @ SEA | 46 | W 5-2 | 21-25 | 4 | 29,522 | Jason Johnson | Jamie Moyer | Jason Johnson | Jamie Moyer | Roberto Hernandez | 185 | 213 | -28 |
| 1998-05-23 | @ SEA | 47 | W 6-3 | 22-25 | 4 | 35,819 | Tony Saunders | Ken Cloude | Esteban Yan | Bobby Ayala | Roberto Hernandez | 191 | 216 | -25 |
| 1998-05-24 | @ SEA | 48 | L 1-3 | 22-26 | 4 | 46,867 | Dennis Springer | Randy Johnson | Randy Johnson | Dennis Springer | | 192 | 219 | -27 |
| 1998-05-25 | @ OAK | 49 | L 2-8 | 22-27 | 4 | 13,199 | Matt Ruebel | Mike Oquist | Mike Oquist | Matt Ruebel | | 194 | 227 | -33 |
| 1998-05-26 | @ OAK | 50 | W 7-2 | 23-27 | 4 | 9,801 | Rolando Arrojo | Tom Candiotti | Rolando Arrojo | Tom Candiotti | | 201 | 229 | -28 |
| 1998-05-28 | vs SEA | 51 | L 2-5 | 23-28 | 5 | 27,017 | Jason Johnson | Jamie Moyer | Jamie Moyer | Jason Johnson | | 203 | 234 | -31 |
| 1998-05-29 | vs SEA | 52 | L 2-6 | 23-29 | 5 | 32,142 | Tony Saunders | Randy Johnson | Randy Johnson | Tony Saunders | | 205 | 240 | -35 |
| 1998-05-30 | vs SEA | 53 | W 5-2 | 24-29 | 5 | 40,212 | Dennis Springer | Ken Cloude | Dennis Springer | Ken Cloude | Roberto Hernandez | 210 | 242 | -32 |
| 1998-05-31 | vs SEA | 54 | L 6-11 | 24-30 | 5 | 35,184 | Rick White | Bill Swift | Bill Swift | Rick White | | 216 | 253 | -37 |
| 1998-06-01 | vs TEX | 55 | W 4-1 | 25-30 | 5 | 24,388 | Rolando Arrojo | John Burkett | Rolando Arrojo | John Burkett | Roberto Hernandez | 220 | 254 | -34 |
| 1998-06-02 | vs TEX | 56 | L 3-7 | 25-31 | 5 | 24,477 | Jason Johnson | Bobby Witt | Bobby Witt | Jason Johnson | | 223 | 261 | -38 |
| 1998-06-03 | @ NYA | 57 | L 1-7 | 25-32 | 5 | 27,291 | Tony Saunders | Orlando Hernandez | Orlando Hernandez | Tony Saunders | | 224 | 268 | -44 |
| 1998-06-04 | @ NYA | 58 | L 1-6 | 25-33 | 5 | 22,759 | Dennis Springer | Hideki Irabu | Hideki Irabu | Dennis Springer | | 225 | 274 | -49 |
| 1998-06-05 | vs MON | 59 | L 2-5 | 25-34 | 5 | 24,025 | Rick White | Dustin Hermanson | Dustin Hermanson | Rick White | | 227 | 279 | -52 |
| 1998-06-06 | vs MON | 60 | L 5-7 | 25-35 | 5 | 26,501 | Rolando Arrojo | Trey Moore | Anthony Telford | Matt Ruebel | Ugueth Urbina | 232 | 286 | -54 |
| 1998-06-07 | vs MON | 61 | W 4-3 | 26-35 | 5 | 26,334 | Jason Johnson | Javier Vazquez | Albie Lopez | Steve Kline | | 236 | 289 | -53 |
| 1998-06-08 | @ NYN | 62 | L 0-3 | 26-36 | 5 | 24,186 | Dennis Springer | Rick Reed | Rick Reed | Dennis Springer | | 236 | 292 | -56 |
| 1998-06-09 | @ NYN | 63 | W 5-4 | 27-36 | 5 | 30,336 | Julio Santana | Hideo Nomo | Jim Mecir | John Hudek | Roberto Hernandez | 241 | 296 | -55 |
| 1998-06-10 | @ NYN | 64 | L 2-3 | 27-37 | 5 | 21,682 | Rick White | Al Leiter | Al Leiter | Rick White | Mel Rojas | 243 | 299 | -56 |
| 1998-06-12 | @ BOS | 65 | L 1-5 | 27-38 | 5 | 31,994 | Rolando Arrojo | Tim Wakefield | Tim Wakefield | Rolando Arrojo | | 244 | 304 | -60 |
| 1998-06-14 | @ BOS | 66 | L 2-3 | 27-39 | 5 | 27,768 | Tony Saunders | Steve Avery | Tom Gordon | Albie Lopez | | 246 | 307 | -61 |
| 1998-06-15 | vs TOR | 67 | W 8-7 | 28-39 | 5 | 24,122 | Julio Santana | Woody Williams | Rick White | Paul Quantrill | Roberto Hernandez | 254 | 314 | -60 |
| 1998-06-16 | vs TOR | 68 | W 4-3 | 29-39 | 5 | 24,278 | Jason Johnson | Pat Hentgen | Jim Mecir | Randy Myers | | 258 | 317 | -59 |
| 1998-06-17 | vs TOR | 69 | W 2-1 | 30-39 | 5 | 24,394 | Rolando Arrojo | Juan Guzman | Rolando Arrojo | Juan Guzman | Roberto Hernandez | 260 | 318 | -58 |
| 1998-06-18 | vs BOS | 70 | L 5-7 | 30-40 | 5 | 30,177 | Dennis Springer | Derek Lowe | John Wasdin | Esteban Yan | Tom Gordon | 265 | 325 | -60 |
| 1998-06-19 | vs BOS | 71 | L 1-4 | 30-41 | 5 | 32,375 | Tony Saunders | Steve Avery | Steve Avery | Tony Saunders | Tom Gordon | 266 | 329 | -63 |
| 1998-06-20 | vs BOS | 72 | W 8-5 | 31-41 | 5 | 41,169 | Julio Santana | Bret Saberhagen | Julio Santana | Bret Saberhagen | Roberto Hernandez | 274 | 334 | -60 |
| 1998-06-21 | vs BOS | 73 | L 1-3 | 31-42 | 5 | 40,348 | Jason Johnson | Pedro Martinez | Pedro Martinez | Jason Johnson | Tom Gordon | 275 | 337 | -62 |
| 1998-06-22 | vs FLO | 74 | L 2-3 | 31-43 | 5 | 25,623 | Rolando Arrojo | Jesus Sanchez | Antonio Alfonseca | Jim Mecir | | 277 | 340 | -63 |
| 1998-06-23 | vs FLO | 75 | W 6-4 | 32-43 | 5 | 27,523 | Dennis Springer | Ryan Dempster | Albie Lopez | Ryan Dempster | Roberto Hernandez | 283 | 344 | -61 |
| 1998-06-24 | @ FLO | 76 | L 4-8 | 32-44 | 5 | 19,501 | Tony Saunders | Brian Meadows | Brian Meadows | Tony Saunders | | 287 | 352 | -65 |
| 1998-06-25 | @ FLO | 77 | L 1-5 | 32-45 | 5 | 16,826 | Julio Santana | Livan Hernandez | Livan Hernandez | Julio Santana | | 288 | 357 | -69 |
| 1998-06-26 | @ PHI | 78 | L 0-7 | 32-46 | 5 | 17,559 | Jason Johnson | Tyler Green | Tyler Green | Jason Johnson | | 288 | 364 | -76 |
| 1998-06-27 | @ PHI | 79 | W 5-1 | 33-46 | 5 | 44,262 | Rolando Arrojo | Curt Schilling | Rolando Arrojo | Curt Schilling | | 293 | 365 | -72 |
| 1998-06-28 | @ PHI | 80 | W 5-4 | 34-46 | 5 | 25,157 | Dennis Springer | Mark Portugal | Albie Lopez | Wayne Gomes | Roberto Hernandez | 298 | 369 | -71 |
| 1998-06-30 | vs ATL | 81 | L 2-7 | 34-47 | 5 | 41,047 | Tony Saunders | Denny Neagle | Denny Neagle | Tony Saunders | | 300 | 376 | -76 |
| 1998-07-01 | vs ATL | 82 | L 5-6 | 34-48 | 5 | 41,100 | Julio Santana | John Smoltz | Russ Springer | Roberto Hernandez | Kerry Ligtenberg | 305 | 382 | -77 |
| 1998-07-02 | vs ATL | 83 | L 0-6 | 34-49 | 5 | 40,749 | Rolando Arrojo | Greg Maddux | Greg Maddux | Rolando Arrojo | | 305 | 388 | -83 |
| 1998-07-03 | @ TOR | 84 | L 2-3 | 34-50 | 5 | 25,625 | Jason Johnson | Juan Guzman | Randy Myers | Esteban Yan | | 307 | 391 | -84 |
| 1998-07-04 | @ TOR | 85 | L 0-8 | 34-51 | 5 | 29,198 | Dennis Springer | Chris Carpenter | Chris Carpenter | Dennis Springer | | 307 | 399 | -92 |
| 1998-07-05 | @ TOR | 86 | L 1-2 | 34-52 | 5 | 31,240 | Tony Saunders | Roger Clemens | Paul Quantrill | Rick White | Randy Myers | 308 | 401 | -93 |
| 1998-07-09 | vs NYA | 87 | L 0-2 | 34-53 | 5 | 38,386 | Bryan Rekar | Andy Pettitte | Andy Pettitte | Bryan Rekar | Mariano Rivera | 308 | 403 | -95 |
| 1998-07-10 | vs NYA | 88 | L 4-8 | 34-54 | 5 | 40,363 | Wilson Alvarez | Hideki Irabu | Hideki Irabu | Wilson Alvarez | Ramiro Mendoza | 312 | 411 | -99 |
| 1998-07-11 | vs NYA | 89 | L 0-2 | 34-55 | 5 | 44,589 | Rolando Arrojo | David Cone | David Cone | Rolando Arrojo | Mariano Rivera | 312 | 413 | -101 |
| 1998-07-12 | vs NYA | 90 | L 2-9 | 34-56 | 5 | 43,373 | Tony Saunders | David Wells | Mike Stanton | Roberto Hernandez | | 314 | 422 | -108 |
| 1998-07-13 | vs BOS | 91 | L 0-2 | 34-57 | 5 | 29,186 | Julio Santana | Steve Avery | Steve Avery | Julio Santana | Tom Gordon | 314 | 424 | -110 |
| 1998-07-14 | vs BOS | 92 | W 5-4 | 35-57 | 5 | 27,310 | Bryan Rekar | Bret Saberhagen | Albie Lopez | Ron Mahay | | 319 | 428 | -109 |
| 1998-07-15 | @ ANA | 93 | L 2-4 | 35-58 | 5 | 19,681 | Wilson Alvarez | Chuck Finley | Shigetoshi Hasegawa | Wilson Alvarez | Troy Percival | 321 | 432 | -111 |
| 1998-07-16 | @ ANA | 94 | W 8-1 | 36-58 | 5 | 24,085 | Rolando Arrojo | Steve Sparks | Rolando Arrojo | Steve Sparks | | 329 | 433 | -104 |
| 1998-07-17 | @ TEX | 95 | L 4-7 | 36-59 | 5 | 33,876 | Tony Saunders | Darren Oliver | Darren Oliver | Jim Mecir | John Wetteland | 333 | 440 | -107 |
| 1998-07-18 | @ TEX | 96 | L 8-9 | 36-60 | 5 | 44,356 | Julio Santana | Esteban Loaiza | Tim Crabtree | Esteban Yan | | 341 | 449 | -108 |
| 1998-07-19 | @ TEX | 97 | L 4-7 | 36-61 | 5 | 34,700 | Bryan Rekar | John Burkett | John Burkett | Bryan Rekar | John Wetteland | 345 | 456 | -111 |
| 1998-07-21 | vs SEA | 98 | L 3-8 | 36-62 | 5 | 30,298 | Wilson Alvarez | Jamie Moyer | Jamie Moyer | Wilson Alvarez | | 348 | 464 | -116 |
| 1998-07-22 | vs SEA | 99 | W 7-5 | 37-62 | 5 | 31,558 | Rolando Arrojo | Randy Johnson | Albie Lopez | Randy Johnson | Roberto Hernandez | 355 | 469 | -114 |
| 1998-07-24 | vs OAK | 100 | W 6-0 | 38-62 | 5 | 25,476 | Tony Saunders | Mike Oquist | Tony Saunders | Mike Oquist | | 361 | 469 | -108 |
| 1998-07-25 | vs OAK | 101 | W 7-5 | 39-62 | 5 | 30,179 | Julio Santana | Kenny Rogers | Roberto Hernandez | Kenny Rogers | | 368 | 474 | -106 |
| 1998-07-26 | vs OAK | 102 | W 3-1 | 40-62 | 5 | 37,194 | Wilson Alvarez | Tom Candiotti | Wilson Alvarez | Tom Candiotti | Esteban Yan | 371 | 475 | -104 |
| 1998-07-27 | vs OAK | 103 | W 11-5 | 41-62 | 5 | 24,359 | Bryan Rekar | Blake Stein | Bryan Rekar | Blake Stein | | 382 | 480 | -98 |
| 1998-07-28 | @ CHA | 104 | L 1-4 | 41-63 | 5 | 18,402 | Rolando Arrojo | James Baldwin | James Baldwin | Rolando Arrojo | Bill Simas | 383 | 484 | -101 |
| 1998-07-29 | @ CHA | 105 | W 7-2 | 42-63 | 5 | 17,387 | Tony Saunders | Jim Parque | Tony Saunders | Jim Parque | | 390 | 486 | -96 |
| 1998-07-31 | vs DET | 106 | W 5-1 | 43-63 | 5 | 25,654 | Julio Santana | Seth Greisinger | Julio Santana | Seth Greisinger | Roberto Hernandez | 395 | 487 | -92 |
| 1998-08-01 | vs DET | 107 | L 0-8 | 43-64 | 5 | 28,130 | Wilson Alvarez | Brian Moehler | Brian Moehler | Wilson Alvarez | | 395 | 495 | -100 |
| 1998-08-02 | vs DET | 108 | L 2-3 | 43-65 | 5 | 26,120 | Bryan Rekar | Brian Powell | Brian Powell | Bryan Rekar | Todd Jones | 397 | 498 | -101 |
| 1998-08-03 | vs CHA | 109 | L 1-6 | 43-66 | 5 | 24,698 | Rolando Arrojo | James Baldwin | James Baldwin | Rolando Arrojo | | 398 | 504 | -106 |
| 1998-08-04 | vs CHA | 110 | L 6-8 | 43-67 | 5 | 24,866 | Tony Saunders | Jim Parque | Carlos Castillo | Tony Saunders | Bill Simas | 404 | 512 | -108 |
| 1998-08-05 | vs CHA | 111 | W 7-3 | 44-67 | 5 | 24,814 | Julio Santana | John Snyder | Roberto Hernandez | Bob Howry | | 411 | 515 | -104 |
| 1998-08-07 | vs CLE | 112 | L 1-5 | 44-68 | 5 | 32,254 | Wilson Alvarez | Dwight Gooden | Dwight Gooden | Wilson Alvarez | | 412 | 520 | -108 |
| 1998-08-08 | vs CLE | 113 | L 2-6 | 44-69 | 5 | 37,108 | Bryan Rekar | Charles Nagy | Charles Nagy | Bryan Rekar | | 414 | 526 | -112 |
| 1998-08-09 | vs CLE | 114 | W 2-1 | 45-69 | 5 | 36,641 | Rolando Arrojo | Jaret Wright | Jim Mecir | Paul Assenmacher | | 416 | 527 | -111 |
| 1998-08-10 | vs BAL | 115 | L 1-2 | 45-70 | 5 | 26,352 | Tony Saunders | Juan Guzman | Juan Guzman | Tony Saunders | Armando Benitez | 417 | 529 | -112 |
| 1998-08-11 | vs BAL | 116 | W 2-1 | 46-70 | 5 | 26,472 | Julio Santana | Scott Kamieniecki | Jim Mecir | Armando Benitez | | 419 | 530 | -111 |
| 1998-08-12 | vs BAL | 117 | L 0-7 | 46-71 | 5 | 29,211 | Wilson Alvarez | Scott Erickson | Scott Erickson | Wilson Alvarez | | 419 | 537 | -118 |
| 1998-08-13 | @ KCA | 118 | L 4-6 | 46-72 | 5 | 18,289 | Bryan Rekar | Pat Rapp | Jeff Montgomery | Roberto Hernandez | | 423 | 543 | -120 |
| 1998-08-14 | @ KCA | 119 | L 9-11 | 46-73 | 5 | 28,133 | Rolando Arrojo | Chris Haney | Chris Haney | Rolando Arrojo | Scott Service | 432 | 554 | -122 |
| 1998-08-15 | @ KCA | 120 | W 8-6 | 47-73 | 5 | 18,706 | Tony Saunders | Hipolito Pichardo | Jim Mecir | Ricky Bones | Roberto Hernandez | 440 | 560 | -120 |
| 1998-08-16 | @ KCA | 121 | W 8-3 | 48-73 | 5 | 16,762 | Julio Santana | Tim Belcher | Julio Santana | Tim Belcher | | 448 | 563 | -115 |
| 1998-08-17 | @ CLE | 122 | L 3-4 | 48-74 | 5 | 43,139 | Wilson Alvarez | Bartolo Colon | Bartolo Colon | Wilson Alvarez | Michael Jackson | 451 | 567 | -116 |
| 1998-08-18 | @ CLE | 123 | L 2-4 | 48-75 | 5 | 42,967 | Bryan Rekar | Dwight Gooden | Dwight Gooden | Bryan Rekar | Michael Jackson | 453 | 571 | -118 |
| 1998-08-19 | @ BAL | 124 | L 4-6 | 48-76 | 5 | 44,530 | Rolando Arrojo | Mike Mussina | Mike Mussina | Rolando Arrojo | Armando Benitez | 457 | 577 | -120 |
| 1998-08-20 | @ BAL | 125 | W 4-2 | 49-76 | 5 | 44,566 | Tony Saunders | Juan Guzman | Tony Saunders | Arthur Rhodes | Roberto Hernandez | 461 | 579 | -118 |
| 1998-08-21 | vs KCA | 126 | L 5-6 | 49-77 | 5 | 25,368 | Julio Santana | Tim Belcher | Matt Whisenant | Esteban Yan | Jeff Montgomery | 466 | 585 | -119 |
| 1998-08-22 | vs KCA | 127 | L 2-3 | 49-78 | 5 | 27,346 | Wilson Alvarez | Jose Rosado | Jose Rosado | Wilson Alvarez | Jeff Montgomery | 468 | 588 | -120 |
| 1998-08-23 | vs KCA | 128 | L 5-11 | 49-79 | 5 | 33,123 | Bryan Rekar | Pat Rapp | Pat Rapp | Bryan Rekar | | 473 | 599 | -126 |
| 1998-08-25 | vs MIN | 129 | L 1-4 | 49-80 | 5 | 23,126 | Rolando Arrojo | Frankie Rodriguez | Frankie Rodriguez | Rolando Arrojo | Rick Aguilera | 474 | 603 | -129 |
| 1998-08-26 | vs MIN | 130 | L 3-7 | 49-81 | 5 | 23,059 | Tony Saunders | Bob Tewksbury | Bob Tewksbury | Tony Saunders | Rick Aguilera | 477 | 610 | -133 |
| 1998-08-27 | vs MIN | 131 | W 10-3 | 50-81 | 5 | 23,314 | Julio Santana | Eric Milton | Julio Santana | Eric Milton | | 487 | 613 | -126 |
| 1998-08-28 | @ DET | 132 | W 4-3 | 51-81 | 5 | 19,534 | Wilson Alvarez | Brian Moehler | Jim Mecir | Brian Moehler | Roberto Hernandez | 491 | 616 | -125 |
| 1998-08-29 | @ DET | 133 | W 10-6 | 52-82 | 5 | 0 | Dennis Springer | Justin Thompson | Dennis Springer | Justin Thompson | | 501 | 622 | -121 |
| 1998-08-29 | @ DET | 134 | L 2-8 | 52-82 | 5 | 16,406 | Bryan Rekar | Seth Greisinger | Seth Greisinger | Bryan Rekar | | 503 | 630 | -127 |
| 1998-08-30 | @ DET | 135 | W 10-5 | 53-82 | 5 | 14,765 | Rolando Arrojo | Brian Powell | Rolando Arrojo | Brian Powell | Roberto Hernandez | 513 | 635 | -122 |
| 1998-08-31 | @ MIN | 136 | L 1-2 | 53-83 | 5 | 7,888 | Tony Saunders | Bob Tewksbury | Bob Tewksbury | Tony Saunders | Rick Aguilera | 514 | 637 | -123 |
| 1998-09-01 | @ MIN | 137 | L 5-6 | 53-84 | 5 | 7,947 | Julio Santana | Eric Milton | Dan Serafini | Roberto Hernandez | | 519 | 643 | -124 |
| 1998-09-02 | @ MIN | 138 | W 4-1 | 54-84 | 5 | 7,165 | Wilson Alvarez | LaTroy Hawkins | Esteban Yan | LaTroy Hawkins | Albie Lopez | 523 | 644 | -121 |
| 1998-09-03 | @ MIN | 139 | L 4-5 | 54-85 | 5 | 7,072 | Bryan Rekar | Brad Radke | Eddie Guardado | Rick White | | 527 | 649 | -122 |
| 1998-09-04 | @ OAK | 140 | W 5-2 | 55-85 | 5 | 8,198 | Rolando Arrojo | Jimmy Haynes | Rolando Arrojo | Jimmy Haynes | Roberto Hernandez | 532 | 651 | -119 |
| 1998-09-05 | @ OAK | 141 | L 0-3 | 55-86 | 5 | 34,193 | Tony Saunders | Kenny Rogers | Kenny Rogers | Tony Saunders | | 532 | 654 | -122 |
| 1998-09-06 | @ OAK | 142 | L 2-9 | 55-87 | 5 | 35,162 | Julio Santana | Tom Candiotti | Tom Candiotti | Julio Santana | | 534 | 663 | -129 |
| 1998-09-08 | @ SEA | 143 | W 10-0 | 56-87 | 5 | 20,679 | Wilson Alvarez | Mac Suzuki | Wilson Alvarez | Mac Suzuki | | 544 | 663 | -119 |
| 1998-09-09 | @ SEA | 144 | L 2-5 | 56-88 | 5 | 22,256 | Rolando Arrojo | Paul Abbott | Paul Abbott | Rolando Arrojo | Mike Timlin | 546 | 668 | -122 |
| 1998-09-11 | vs TEX | 145 | W 3-2 | 57-88 | 5 | 28,522 | Tony Saunders | Todd Stottlemyre | Tony Saunders | Todd Stottlemyre | Roberto Hernandez | 549 | 670 | -121 |
| 1998-09-12 | vs TEX | 146 | L 2-8 | 57-89 | 5 | 31,278 | Julio Santana | Rick Helling | Rick Helling | Julio Santana | | 551 | 678 | -127 |
| 1998-09-13 | vs TEX | 147 | W 10-5 | 58-89 | 5 | 34,007 | Bryan Rekar | Esteban Loaiza | Rick White | Esteban Loaiza | | 561 | 683 | -122 |
| 1998-09-14 | vs ANA | 148 | L 2-4 | 58-90 | 5 | 24,279 | Wilson Alvarez | Omar Olivares | Shigetoshi Hasegawa | Albie Lopez | Troy Percival | 563 | 687 | -124 |
| 1998-09-15 | vs ANA | 149 | W 8-1 | 59-90 | 5 | 24,347 | Rolando Arrojo | Jeff Juden | Rolando Arrojo | Jeff Juden | | 571 | 688 | -117 |
| 1998-09-16 | vs NYA | 150 | W 7-0 | 60-90 | 5 | 38,862 | Tony Saunders | Andy Pettitte | Tony Saunders | Andy Pettitte | | 578 | 688 | -110 |
| 1998-09-17 | vs NYA | 151 | L 0-4 | 60-91 | 5 | 38,820 | Julio Santana | Hideki Irabu | Hideki Irabu | Julio Santana | | 578 | 692 | -114 |
| 1998-09-18 | vs TOR | 152 | W 6-1 | 61-91 | 5 | 32,053 | Bryan Rekar | Kelvim Escobar | Bryan Rekar | Kelvim Escobar | | 584 | 693 | -109 |
| 1998-09-19 | vs TOR | 153 | W 7-5 | 62-91 | 5 | 35,689 | Wilson Alvarez | Woody Williams | Albie Lopez | Ben VanRyn | Roberto Hernandez | 591 | 698 | -107 |
| 1998-09-20 | vs TOR | 154 | L 5-7 | 62-92 | 5 | 32,183 | Rolando Arrojo | Roy Halladay | Bill Risley | Albie Lopez | | 596 | 705 | -109 |
| 1998-09-21 | @ BOS | 155 | L 3-4 | 63-93 | 5 | 0 | Tony Saunders | Bret Saberhagen | Bret Saberhagen | Tony Saunders | Tom Gordon | 599 | 709 | -110 |
| 1998-09-21 | @ BOS | 156 | W 8-4 | 63-93 | 5 | 23,379 | Terrell Wade | John Wasdin | Terrell Wade | Carlos Reyes | | 607 | 713 | -106 |
| 1998-09-22 | @ BOS | 157 | L 2-11 | 63-94 | 5 | 20,399 | Julio Santana | Pete Schourek | Pete Schourek | Julio Santana | | 609 | 724 | -115 |
| 1998-09-23 | @ BOS | 158 | L 4-5 | 63-95 | 5 | 23,240 | Bryan Rekar | Steve Avery | Steve Avery | Bryan Rekar | Tom Gordon | 613 | 729 | -116 |
| 1998-09-24 | @ NYA | 159 | L 2-5 | 63-96 | 5 | 24,555 | Wilson Alvarez | David Wells | Mike Buddie | Wilson Alvarez | Jeff Nelson | 615 | 734 | -119 |
| 1998-09-25 | @ NYA | 160 | L 1-6 | 63-97 | 5 | 32,447 | Dave Eiland | Orlando Hernandez | Orlando Hernandez | Dave Eiland | | 616 | 740 | -124 |
| 1998-09-26 | @ NYA | 161 | L 1-3 | 63-98 | 5 | 41,150 | Terrell Wade | David Cone | David Cone | Terrell Wade | | 617 | 743 | -126 |
| 1998-09-27 | @ NYA | 162 | L 3-8 | 63-99 | 5 | 49,608 | Bryan Rekar | Jim Bruske | Jim Bruske | Rick White | | 620 | 751 | -131 |