| 1989-04-03 | @ OAK | 1 | L 2-3 | 0-1 | 5 | 46,163 | Mark Langston | Dave Stewart | Dave Stewart | Mark Langston | Dennis Eckersley | 2 | 3 | -1 |
| 1989-04-05 | @ OAK | 2 | L 1-11 | 0-2 | 7 | 16,045 | Scott Bankhead | Bob Welch | Bob Welch | Scott Bankhead | | 3 | 14 | -11 |
| 1989-04-06 | @ OAK | 3 | L 3-11 | 0-3 | 7 | 19,087 | Mike Campbell | Storm Davis | Storm Davis | Mike Campbell | Todd Burns | 6 | 25 | -19 |
| 1989-04-07 | @ CAL | 4 | L 1-2 | 0-4 | 7 | 22,822 | Erik Hanson | Kirk McCaskill | Kirk McCaskill | Erik Hanson | Bryan Harvey | 7 | 27 | -20 |
| 1989-04-08 | @ CAL | 5 | W 7-0 | 1-4 | 7 | 46,847 | Mark Langston | Jim Abbott | Mark Langston | Jim Abbott | | 14 | 27 | -13 |
| 1989-04-09 | @ CAL | 6 | L 5-13 | 1-5 | 7 | 23,226 | Steve Trout | Mike Witt | Mike Witt | Steve Trout | | 19 | 40 | -21 |
| 1989-04-10 | vs CHA | 7 | W 6-5 | 2-5 | 7 | 33,866 | Scott Bankhead | Eric King | Jerry Reed | Eric King | Mike Schooler | 25 | 45 | -20 |
| 1989-04-11 | vs CHA | 8 | L 6-8 | 2-6 | 7 | 8,088 | Mike Campbell | Shawn Hillegas | Barry Jones | Tom Niedenfuer | Bobby Thigpen | 31 | 53 | -22 |
| 1989-04-12 | vs CHA | 9 | W 9-1 | 3-6 | 7 | 8,190 | Erik Hanson | Bill Long | Erik Hanson | Bill Long | | 40 | 54 | -14 |
| 1989-04-14 | vs CAL | 10 | W 9-5 | 4-6 | 7 | 14,590 | Mark Langston | Mike Witt | Mark Langston | Mike Witt | | 49 | 59 | -10 |
| 1989-04-15 | vs CAL | 11 | L 2-9 | 4-7 | 7 | 29,819 | Scott Bankhead | Chuck Finley | Chuck Finley | Jerry Reed | | 51 | 68 | -17 |
| 1989-04-16 | vs CAL | 12 | L 0-10 | 4-8 | 7 | 10,621 | Mike Campbell | Bert Blyleven | Bert Blyleven | Mike Campbell | | 51 | 78 | -27 |
| 1989-04-17 | vs OAK | 13 | W 7-2 | 5-8 | 7 | 14,827 | Erik Hanson | Curt Young | Erik Hanson | Curt Young | | 58 | 80 | -22 |
| 1989-04-18 | vs OAK | 14 | L 3-5 | 5-9 | 7 | 9,670 | Steve Trout | Mike Moore | Eric Plunk | Jerry Reed | Dennis Eckersley | 61 | 85 | -24 |
| 1989-04-19 | vs OAK | 15 | L 5-7 | 5-10 | 7 | 11,328 | Mark Langston | Dave Stewart | Dave Stewart | Mark Langston | Dennis Eckersley | 66 | 92 | -26 |
| 1989-04-20 | @ CHA | 16 | W 5-2 | 6-10 | 7 | 6,467 | Scott Bankhead | Melido Perez | Scott Bankhead | Barry Jones | | 71 | 94 | -23 |
| 1989-04-21 | @ CHA | 17 | W 11-1 | 7-10 | 6 | 7,652 | Mike Campbell | Jerry Reuss | Mike Campbell | Jerry Reuss | | 82 | 95 | -13 |
| 1989-04-22 | @ CHA | 18 | L 0-1 | 7-11 | 7 | 15,007 | Erik Hanson | Eric King | Eric King | Erik Hanson | | 82 | 96 | -14 |
| 1989-04-23 | @ CHA | 19 | W 10-6 | 8-11 | 6 | 11,216 | Steve Trout | Shawn Hillegas | Steve Trout | Shawn Hillegas | | 92 | 102 | -10 |
| 1989-04-24 | @ DET | 20 | L 0-1 | 8-12 | 6 | 13,174 | Mark Langston | Doyle Alexander | Doyle Alexander | Mark Langston | | 92 | 103 | -11 |
| 1989-04-25 | @ DET | 21 | L 2-5 | 8-13 | 6 | 12,043 | Scott Bankhead | Frank Tanana | Frank Tanana | Scott Bankhead | Guillermo Hernandez | 94 | 108 | -14 |
| 1989-04-26 | vs TOR | 22 | W 7-6 | 9-13 | 6 | 7,399 | Mike Campbell | Dave Stieb | Steve Trout | David Wells | Michael Jackson | 101 | 114 | -13 |
| 1989-04-27 | vs TOR | 23 | L 1-6 | 9-14 | 6 | 8,600 | Mike Dunne | Mike Flanagan | Mike Flanagan | Mike Dunne | | 102 | 120 | -18 |
| 1989-04-28 | vs BAL | 24 | W 11-5 | 10-14 | 6 | 10,929 | Erik Hanson | Bob Milacki | Jerry Reed | Brian Holton | | 113 | 125 | -12 |
| 1989-04-29 | vs BAL | 25 | W 4-3 | 11-14 | 5 | 14,688 | Mark Langston | Dave J. Schmidt | Mark Langston | Dave J. Schmidt | Mike Schooler | 117 | 128 | -11 |
| 1989-04-30 | vs BAL | 26 | L 3-4 | 11-15 | 6 | 9,452 | Scott Bankhead | Jeff Ballard | Jeff Ballard | Steve Trout | Mark Williamson | 120 | 132 | -12 |
| 1989-05-01 | vs DET | 27 | W 5-3 | 12-15 | 5 | 14,788 | Bill Swift | Jack Morris | Dennis Powell | Jack Morris | Mike Schooler | 125 | 135 | -10 |
| 1989-05-02 | vs DET | 28 | W 7-2 | 13-15 | 5 | 10,534 | Mike Dunne | Charles Hudson | Mike Dunne | Charles Hudson | Michael Jackson | 132 | 137 | -5 |
| 1989-05-03 | vs DET | 29 | W 3-2 | 14-15 | 5 | 9,130 | Erik Hanson | Doyle Alexander | Erik Hanson | Doyle Alexander | Mike Schooler | 135 | 139 | -4 |
| 1989-05-06 | @ BAL | 30 | W 2-1 | 16-15 | 5 | 0 | Mark Langston | Dave J. Schmidt | Mark Langston | Dave J. Schmidt | Mike Schooler | 137 | 140 | -3 |
| 1989-05-06 | @ BAL | 31 | W 6-5 | 16-15 | 5 | 19,975 | Scott Bankhead | Jeff Ballard | Scott Bankhead | Jeff Ballard | Mike Schooler | 143 | 145 | -2 |
| 1989-05-07 | @ BAL | 32 | W 5-3 | 17-15 | 5 | 25,982 | Bill Swift | Jose Bautista | Bill Swift | Jose Bautista | Dennis Powell | 148 | 148 | 0 |
| 1989-05-08 | @ TOR | 33 | L 1-10 | 17-16 | 5 | 23,293 | Mike Dunne | Dave Stieb | Dave Stieb | Mike Dunne | | 149 | 158 | -9 |
| 1989-05-09 | @ TOR | 34 | W 4-3 | 18-16 | 5 | 24,234 | Erik Hanson | Mike Flanagan | Erik Hanson | Mike Flanagan | Mike Schooler | 153 | 161 | -8 |
| 1989-05-10 | @ TOR | 35 | L 2-3 | 18-17 | 5 | 33,216 | Mark Langston | Jimmy Key | Jimmy Key | Mark Langston | | 155 | 164 | -9 |
| 1989-05-12 | vs BOS | 36 | L 0-2 | 18-18 | 5 | 25,239 | Scott Bankhead | Roger Clemens | Roger Clemens | Scott Bankhead | | 155 | 166 | -11 |
| 1989-05-13 | vs BOS | 37 | W 14-6 | 19-18 | 5 | 29,689 | Bill Swift | John Dopson | Jerry Reed | John Dopson | | 169 | 172 | -3 |
| 1989-05-14 | vs BOS | 38 | W 4-3 | 20-18 | 5 | 13,618 | Erik Hanson | Mike Boddicker | Steve Trout | Mike Boddicker | Mike Schooler | 173 | 175 | -2 |
| 1989-05-16 | vs MIL | 39 | W 6-5 | 21-18 | 5 | 9,651 | Mark Langston | Teddy Higuera | Michael Jackson | Bill Wegman | Mike Schooler | 179 | 180 | -1 |
| 1989-05-17 | vs MIL | 40 | L 6-9 | 21-19 | 5 | 9,271 | Scott Bankhead | Mike Birkbeck | Chuck Crim | Scott Bankhead | Dan Plesac | 185 | 189 | -4 |
| 1989-05-18 | vs MIL | 41 | W 9-5 | 22-19 | 5 | 9,416 | Bill Swift | Chris Bosio | Bill Swift | Chris Bosio | Mike Schooler | 194 | 194 | 0 |
| 1989-05-19 | vs NYA | 42 | L 5-9 | 22-20 | 5 | 39,340 | Erik Hanson | Andy Hawkins | Andy Hawkins | Erik Hanson | Lee Guetterman | 199 | 203 | -4 |
| 1989-05-20 | vs NYA | 43 | W 6-4 | 23-20 | 5 | 40,563 | Mike Dunne | Dave LaPoint | Steve Trout | Dave LaPoint | Mike Schooler | 205 | 207 | -2 |
| 1989-05-21 | vs NYA | 44 | L 2-6 | 23-21 | 5 | 35,524 | Mark Langston | Clay Parker | Clay Parker | Mark Langston | | 207 | 213 | -6 |
| 1989-05-23 | @ BOS | 45 | L 5-6 | 23-22 | 5 | 28,069 | Bill Swift | John Dopson | Lee Smith | Jerry Reed | | 212 | 219 | -7 |
| 1989-05-24 | @ BOS | 46 | L 5-6 | 23-23 | 5 | 23,784 | Erik Hanson | Mike Boddicker | Mike Boddicker | Erik Hanson | Lee Smith | 217 | 225 | -8 |
| 1989-05-25 | @ BOS | 47 | L 0-10 | 23-24 | 5 | 26,335 | Mike Dunne | Mike Smithson | Mike Smithson | Mike Dunne | | 217 | 235 | -18 |
| 1989-05-26 | @ MIL | 48 | W 7-2 | 24-24 | 5 | 16,561 | Luis DeLeon | Don August | Michael Jackson | Don August | | 224 | 237 | -13 |
| 1989-05-27 | @ MIL | 49 | L 2-3 | 24-25 | 5 | 26,094 | Scott Bankhead | Teddy Higuera | Dan Plesac | Brian Holman | | 226 | 240 | -14 |
| 1989-05-28 | @ MIL | 50 | L 4-6 | 24-26 | 5 | 30,959 | Bill Swift | Chris Bosio | Chuck Crim | Dennis Powell | Dan Plesac | 230 | 246 | -16 |
| 1989-05-29 | @ NYA | 51 | L 3-6 | 24-27 | 5 | 31,897 | Dennis Powell | Richard Dotson | Richard Dotson | Dennis Powell | Dave Righetti | 233 | 252 | -19 |
| 1989-05-30 | @ NYA | 52 | W 3-2 | 25-27 | 5 | 15,275 | Randy Johnson | Jimmy Jones | Randy Johnson | Jimmy Jones | Mike Schooler | 236 | 254 | -18 |
| 1989-05-31 | @ NYA | 53 | L 5-9 | 25-28 | 5 | 22,946 | Brian Holman | Andy Hawkins | Andy Hawkins | Steve Trout | Lee Guetterman | 241 | 263 | -22 |
| 1989-06-01 | vs TEX | 54 | W 3-2 | 26-28 | 5 | 3,558 | Scott Bankhead | Kevin Brown | Mike Schooler | Kevin Brown | | 244 | 265 | -21 |
| 1989-06-02 | vs TEX | 55 | L 5-9 | 26-29 | 5 | 11,797 | Bill Swift | Mike Jeffcoat | Mike Jeffcoat | Bill Swift | Cecilio Guante | 249 | 274 | -25 |
| 1989-06-03 | vs TEX | 56 | L 1-6 | 26-30 | 6 | 24,601 | Clint Zavaras | Nolan Ryan | Nolan Ryan | Clint Zavaras | | 250 | 280 | -30 |
| 1989-06-04 | vs TEX | 57 | W 2-1 | 27-30 | 5 | 11,784 | Randy Johnson | Charlie Hough | Randy Johnson | Charlie Hough | Mike Schooler | 252 | 281 | -29 |
| 1989-06-05 | vs KCA | 58 | L 3-5 | 27-31 | 6 | 17,429 | Brian Holman | Floyd Bannister | Tom Gordon | Tom Niedenfuer | | 255 | 286 | -31 |
| 1989-06-06 | vs KCA | 59 | W 5-2 | 28-31 | 5 | 10,171 | Scott Bankhead | Stan Clarke | Scott Bankhead | Stan Clarke | | 260 | 288 | -28 |
| 1989-06-07 | vs KCA | 60 | L 6-9 | 28-32 | 5 | 10,925 | Bill Swift | Mark Gubicza | Mark Gubicza | Bill Swift | Jeff Montgomery | 266 | 297 | -31 |
| 1989-06-09 | @ CLE | 61 | L 4-5 | 28-33 | 5 | 59,671 | Clint Zavaras | Tom Candiotti | Tom Candiotti | Clint Zavaras | Doug Jones | 270 | 302 | -32 |
| 1989-06-10 | @ CLE | 62 | W 3-1 | 29-33 | 5 | 11,480 | Randy Johnson | John Farrell | Randy Johnson | John Farrell | Mike Schooler | 273 | 303 | -30 |
| 1989-06-11 | @ CLE | 63 | W 6-3 | 30-33 | 5 | 25,390 | Brian Holman | Buddy Black | Brian Holman | Buddy Black | Gene Harris | 279 | 306 | -27 |
| 1989-06-13 | @ MIN | 64 | L 3-4 | 30-34 | 6 | 18,839 | Scott Bankhead | Frank Viola | Gary Wayne | Jerry Reed | | 282 | 310 | -28 |
| 1989-06-14 | @ MIN | 65 | L 8-10 | 30-35 | 6 | 21,816 | Bill Swift | Roy Smith | Juan Berenguer | Tom Niedenfuer | Jeff Reardon | 290 | 320 | -30 |
| 1989-06-15 | @ MIN | 66 | W 9-5 | 31-35 | 6 | 25,416 | Randy Johnson | Francisco Oliveras | Dennis Powell | Steve Shields | Michael Jackson | 299 | 325 | -26 |
| 1989-06-16 | @ TOR | 67 | L 3-4 | 31-36 | 6 | 48,363 | Brian Holman | Mike Flanagan | Tom Henke | Mike Schooler | | 302 | 329 | -27 |
| 1989-06-17 | @ TOR | 68 | L 2-3 | 31-37 | 6 | 48,336 | Gene Harris | John Cerutti | Duane Ward | Michael Jackson | | 304 | 332 | -28 |
| 1989-06-18 | @ TOR | 69 | W 8-2 | 32-37 | 6 | 48,329 | Scott Bankhead | Frank Wills | Scott Bankhead | Frank Wills | | 312 | 334 | -22 |
| 1989-06-19 | vs BAL | 70 | L 5-9 | 32-38 | 6 | 17,623 | Bill Swift | Bob Milacki | Bob Milacki | Michael Jackson | Mark Thurmond | 317 | 343 | -26 |
| 1989-06-20 | vs BAL | 71 | L 6-8 | 32-39 | 6 | 10,547 | Randy Johnson | Jeff Ballard | Mickey Weston | Jerry Reed | Gregg Olson | 323 | 351 | -28 |
| 1989-06-21 | vs BAL | 72 | L 6-8 | 32-40 | 6 | 11,225 | Brian Holman | Jay Tibbs | Jay Tibbs | Brian Holman | Gregg Olson | 329 | 359 | -30 |
| 1989-06-23 | vs DET | 73 | L 4-5 | 32-41 | 6 | 14,007 | Gene Harris | Doyle Alexander | Mike Henneman | Mike Schooler | | 333 | 364 | -31 |
| 1989-06-24 | vs DET | 74 | W 3-1 | 33-41 | 6 | 15,824 | Scott Bankhead | Frank Tanana | Scott Bankhead | Frank Tanana | Mike Schooler | 336 | 365 | -29 |
| 1989-06-25 | vs DET | 75 | W 5-3 | 34-41 | 6 | 19,950 | Bill Swift | David Palmer | Bill Swift | David Palmer | Michael Jackson | 341 | 368 | -27 |
| 1989-06-27 | @ KCA | 76 | W 8-0 | 35-41 | 6 | 25,164 | Brian Holman | Luis Aquino | Brian Holman | Luis Aquino | | 349 | 368 | -19 |
| 1989-06-28 | @ KCA | 77 | L 7-12 | 35-42 | 6 | 30,037 | Gene Harris | Mark Gubicza | Mark Gubicza | Gene Harris | | 356 | 380 | -24 |
| 1989-06-29 | @ TEX | 78 | W 2-0 | 36-42 | 6 | 26,244 | Scott Bankhead | Charlie Hough | Scott Bankhead | Charlie Hough | Mike Schooler | 358 | 380 | -22 |
| 1989-06-30 | @ TEX | 79 | W 4-3 | 37-42 | 6 | 28,338 | Bill Swift | Nolan Ryan | Bill Swift | Nolan Ryan | Mike Schooler | 362 | 383 | -21 |
| 1989-07-01 | @ TEX | 80 | L 0-1 | 37-43 | 6 | 31,114 | Randy Johnson | Bobby Witt | Bobby Witt | Randy Johnson | Jeff Russell | 362 | 384 | -22 |
| 1989-07-04 | vs MIN | 81 | W 3-2 | 38-43 | 6 | 22,180 | Scott Bankhead | Allan Anderson | Scott Bankhead | Allan Anderson | Mike Schooler | 365 | 386 | -21 |
| 1989-07-05 | vs MIN | 82 | W 7-3 | 39-43 | 6 | 10,383 | Gene Harris | Mike Dyer | Gene Harris | Mike Dyer | Mike Schooler | 372 | 389 | -17 |
| 1989-07-06 | vs MIN | 83 | W 7-5 | 40-43 | 6 | 12,565 | Bill Swift | Shane Rawley | Michael Jackson | Gary Wayne | Mike Schooler | 379 | 394 | -15 |
| 1989-07-07 | vs CLE | 84 | L 3-4 | 40-44 | 6 | 12,096 | Randy Johnson | John Farrell | Doug Jones | Michael Jackson | | 382 | 398 | -16 |
| 1989-07-08 | vs CLE | 85 | W 4-3 | 41-44 | 5 | 15,229 | Brian Holman | Buddy Black | Bill Swift | Jesse Orosco | | 386 | 401 | -15 |
| 1989-07-09 | vs CLE | 86 | W 8-0 | 42-44 | 5 | 14,022 | Scott Bankhead | Scott Bailes | Scott Bankhead | Scott Bailes | | 394 | 401 | -7 |
| 1989-07-13 | @ DET | 87 | W 5-4 | 43-44 | 5 | 14,879 | Randy Johnson | Paul Gibson | Bill Swift | Mike Schwabe | | 399 | 405 | -6 |
| 1989-07-14 | @ DET | 88 | W 13-0 | 44-44 | 5 | 18,059 | Brian Holman | Doyle Alexander | Brian Holman | Doyle Alexander | | 412 | 405 | 7 |
| 1989-07-15 | @ DET | 89 | W 9-3 | 45-44 | 5 | 22,894 | Scott Bankhead | Kevin Ritz | Scott Bankhead | Kevin Ritz | | 421 | 408 | 13 |
| 1989-07-16 | @ DET | 90 | L 5-8 | 45-45 | 5 | 21,768 | Gene Harris | Charles Hudson | Charles Hudson | Gene Harris | Ed Nunez | 426 | 416 | 10 |
| 1989-07-17 | @ BAL | 91 | L 4-8 | 45-46 | 5 | 36,129 | Mike Dunne | Pete Harnisch | Pete Harnisch | Mike Dunne | | 430 | 424 | 6 |
| 1989-07-18 | @ BAL | 92 | L 3-4 | 45-47 | 5 | 29,705 | Randy Johnson | Jeff Ballard | Jeff Ballard | Randy Johnson | Gregg Olson | 433 | 428 | 5 |
| 1989-07-19 | @ BAL | 93 | W 7-0 | 46-47 | 5 | 35,691 | Brian Holman | Brian Holton | Brian Holman | Brian Holton | | 440 | 428 | 12 |
| 1989-07-20 | vs TOR | 94 | W 5-2 | 47-47 | 5 | 15,723 | Scott Bankhead | Dave Stieb | Scott Bankhead | Dave Stieb | Dennis Powell | 445 | 430 | 15 |
| 1989-07-21 | vs TOR | 95 | L 1-8 | 47-48 | 5 | 17,591 | Gene Harris | Mike Flanagan | Mike Flanagan | Gene Harris | | 446 | 438 | 8 |
| 1989-07-22 | vs TOR | 96 | L 1-7 | 47-49 | 5 | 22,044 | Mike Dunne | John Cerutti | John Cerutti | Mike Dunne | Duane Ward | 447 | 445 | 2 |
| 1989-07-23 | vs TOR | 97 | W 5-2 | 48-49 | 5 | 17,973 | Randy Johnson | Jimmy Key | Randy Johnson | Jimmy Key | | 452 | 447 | 5 |
| 1989-07-24 | @ CHA | 98 | L 4-5 | 48-50 | 5 | 11,430 | Brian Holman | Jerry Reuss | Shawn Hillegas | Michael Jackson | | 456 | 452 | 4 |
| 1989-07-25 | @ CHA | 99 | L 6-7 | 48-51 | 5 | 9,185 | Scott Bankhead | Eric King | Donn Pall | Michael Jackson | Bobby Thigpen | 462 | 459 | 3 |
| 1989-07-26 | @ CHA | 100 | L 3-5 | 48-52 | 6 | 14,430 | Bill Swift | Greg Hibbard | Greg Hibbard | Bill Swift | Bobby Thigpen | 465 | 464 | 1 |
| 1989-07-28 | @ OAK | 101 | L 7-8 | 48-53 | 6 | 36,446 | Mike Dunne | Bob Welch | Todd Burns | Gene Harris | | 472 | 472 | 0 |
| 1989-07-29 | @ OAK | 102 | W 14-6 | 49-53 | 6 | 40,734 | Randy Johnson | Storm Davis | Randy Johnson | Storm Davis | Bill Swift | 486 | 478 | 8 |
| 1989-07-30 | @ OAK | 103 | L 3-5 | 49-54 | 6 | 43,898 | Brian Holman | Dave Stewart | Dave Stewart | Brian Holman | Dennis Eckersley | 489 | 483 | 6 |
| 1989-07-31 | vs CAL | 104 | W 6-5 | 50-54 | 6 | 19,494 | Scott Bankhead | Mike Witt | Keith Comstock | Bryan Harvey | Mike Schooler | 495 | 488 | 7 |
| 1989-08-01 | vs CAL | 105 | W 8-1 | 51-54 | 6 | 16,533 | Mike Dunne | Jim Abbott | Mike Dunne | Jim Abbott | | 503 | 489 | 14 |
| 1989-08-02 | vs CAL | 106 | L 0-7 | 51-55 | 6 | 11,460 | Jerry Reed | Bert Blyleven | Bert Blyleven | Jerry Reed | | 503 | 496 | 7 |
| 1989-08-03 | vs CAL | 107 | L 0-6 | 51-56 | 6 | 12,584 | Randy Johnson | Kirk McCaskill | Kirk McCaskill | Randy Johnson | | 503 | 502 | 1 |
| 1989-08-04 | vs OAK | 108 | L 3-5 | 51-57 | 6 | 23,621 | Brian Holman | Dave Stewart | Dave Stewart | Brian Holman | Dennis Eckersley | 506 | 507 | -1 |
| 1989-08-05 | vs OAK | 109 | W 11-5 | 52-57 | 6 | 36,961 | Scott Bankhead | Mike Moore | Scott Bankhead | Mike Moore | Michael Jackson | 517 | 512 | 5 |
| 1989-08-06 | vs OAK | 110 | L 1-2 | 52-58 | 6 | 19,303 | Mike Dunne | Storm Davis | Storm Davis | Mike Dunne | Dennis Eckersley | 518 | 514 | 4 |
| 1989-08-07 | vs OAK | 111 | W 5-1 | 53-58 | 6 | 31,334 | Clint Zavaras | Bob Welch | Clint Zavaras | Bob Welch | | 523 | 515 | 8 |
| 1989-08-08 | @ CAL | 112 | W 6-4 | 54-58 | 6 | 27,252 | Randy Johnson | Bert Blyleven | Jerry Reed | Greg Minton | Mike Schooler | 529 | 519 | 10 |
| 1989-08-09 | @ CAL | 113 | L 1-4 | 54-59 | 6 | 26,416 | Brian Holman | Kirk McCaskill | Kirk McCaskill | Brian Holman | Bryan Harvey | 530 | 523 | 7 |
| 1989-08-10 | @ CAL | 114 | W 3-2 | 55-59 | 6 | 26,924 | Scott Bankhead | Chuck Finley | Michael Jackson | Chuck Finley | Mike Schooler | 533 | 525 | 8 |
| 1989-08-11 | vs CHA | 115 | L 6-9 | 55-60 | 6 | 10,875 | Mike Dunne | Eric King | Bobby Thigpen | Mike Schooler | | 539 | 534 | 5 |
| 1989-08-12 | vs CHA | 116 | W 4-3 | 56-60 | 6 | 14,420 | Clint Zavaras | Greg Hibbard | Jerry Reed | Donn Pall | | 543 | 537 | 6 |
| 1989-08-13 | vs CHA | 117 | L 4-6 | 56-61 | 6 | 20,838 | Randy Johnson | Melido Perez | Bill Long | Keith Comstock | Bobby Thigpen | 547 | 543 | 4 |
| 1989-08-15 | vs TEX | 118 | W 2-0 | 57-61 | 6 | 11,330 | Brian Holman | Charlie Hough | Brian Holman | Charlie Hough | Mike Schooler | 549 | 543 | 6 |
| 1989-08-16 | vs TEX | 119 | L 1-3 | 57-62 | 6 | 16,873 | Scott Bankhead | Nolan Ryan | Nolan Ryan | Scott Bankhead | Jeff Russell | 550 | 546 | 4 |
| 1989-08-17 | vs KCA | 120 | L 2-4 | 57-63 | 6 | 13,720 | Mike Dunne | Mark Gubicza | Mark Gubicza | Mike Dunne | Jeff Montgomery | 552 | 550 | 2 |
| 1989-08-18 | vs KCA | 121 | L 1-3 | 57-64 | 6 | 16,089 | Clint Zavaras | Tom Gordon | Tom Gordon | Clint Zavaras | Jeff Montgomery | 553 | 553 | 0 |
| 1989-08-19 | vs KCA | 122 | L 5-13 | 57-65 | 6 | 24,592 | Randy Johnson | Luis Aquino | Terry Leach | Randy Johnson | | 558 | 566 | -8 |
| 1989-08-20 | vs KCA | 123 | L 4-5 | 57-66 | 6 | 38,729 | Brian Holman | Charlie Leibrandt | Steve Crawford | Brian Holman | Jeff Montgomery | 562 | 571 | -9 |
| 1989-08-22 | @ CLE | 124 | L 2-3 | 57-67 | 6 | 12,565 | Scott Bankhead | John Farrell | Doug Jones | Mike Schooler | | 564 | 574 | -10 |
| 1989-08-23 | @ CLE | 125 | L 3-5 | 57-68 | 6 | 9,618 | Mike Dunne | Tom Candiotti | Tom Candiotti | Mike Dunne | Doug Jones | 567 | 579 | -12 |
| 1989-08-24 | @ CLE | 126 | L 2-5 | 57-69 | 6 | 12,726 | Clint Zavaras | Steve Davis | Steve Davis | Clint Zavaras | Doug Jones | 569 | 584 | -15 |
| 1989-08-25 | @ MIN | 127 | L 1-2 | 57-70 | 6 | 22,195 | Randy Johnson | Mike Dyer | Mike Dyer | Randy Johnson | Jeff Reardon | 570 | 586 | -16 |
| 1989-08-26 | @ MIN | 128 | L 0-1 | 57-71 | 6 | 25,557 | Brian Holman | David West | David West | Brian Holman | Jeff Reardon | 570 | 587 | -17 |
| 1989-08-27 | @ MIN | 129 | L 5-8 | 57-72 | 6 | 32,329 | Scott Bankhead | Mark Guthrie | Mark Guthrie | Scott Bankhead | Juan Berenguer | 575 | 595 | -20 |
| 1989-08-28 | @ MIN | 130 | L 4-5 | 57-73 | 6 | 18,287 | Mike Dunne | Roy Smith | Jeff Reardon | Mike Schooler | | 579 | 600 | -21 |
| 1989-08-29 | @ MIL | 131 | W 5-3 | 58-73 | 6 | 15,720 | Erik Hanson | Jaime Navarro | Erik Hanson | Jaime Navarro | Mike Schooler | 584 | 603 | -19 |
| 1989-08-30 | @ MIL | 132 | W 7-3 | 59-73 | 6 | 13,938 | Randy Johnson | Jeff Peterek | Randy Johnson | Jeff Peterek | Michael Jackson | 591 | 606 | -15 |
| 1989-08-31 | @ MIL | 133 | L 1-6 | 59-74 | 6 | 15,540 | Brian Holman | Mark Knudson | Mark Knudson | Brian Holman | | 592 | 612 | -20 |
| 1989-09-01 | @ BOS | 134 | W 7-2 | 60-74 | 6 | 31,581 | Scott Bankhead | Mike Smithson | Scott Bankhead | Mike Smithson | Michael Jackson | 599 | 614 | -15 |
| 1989-09-02 | @ BOS | 135 | L 5-6 | 60-75 | 6 | 33,615 | Mike Dunne | Mike Boddicker | Dennis Lamp | Mike Dunne | Lee Smith | 604 | 620 | -16 |
| 1989-09-03 | @ BOS | 136 | W 3-2 | 61-75 | 6 | 35,035 | Erik Hanson | Oil Can Boyd | Erik Hanson | Oil Can Boyd | Mike Schooler | 607 | 622 | -15 |
| 1989-09-05 | vs NYA | 137 | L 2-12 | 61-76 | 6 | 14,905 | Randy Johnson | Eric Plunk | Eric Plunk | Randy Johnson | | 609 | 634 | -25 |
| 1989-09-06 | vs NYA | 138 | L 3-5 | 61-77 | 6 | 13,364 | Brian Holman | Walt Terrell | Walt Terrell | Brian Holman | Dave Righetti | 612 | 639 | -27 |
| 1989-09-07 | vs NYA | 139 | L 4-6 | 61-78 | 6 | 11,166 | Scott Bankhead | Greg Cadaret | Rich Gossage | Mike Schooler | Dave Righetti | 616 | 645 | -29 |
| 1989-09-08 | vs MIL | 140 | L 3-7 | 61-79 | 6 | 11,214 | Clint Zavaras | Jaime Navarro | Jaime Navarro | Clint Zavaras | | 619 | 652 | -33 |
| 1989-09-09 | vs MIL | 141 | L 3-7 | 61-80 | 6 | 11,179 | Erik Hanson | Jerry Reuss | Jerry Reuss | Erik Hanson | | 622 | 659 | -37 |
| 1989-09-10 | vs MIL | 142 | L 1-7 | 61-81 | 6 | 8,888 | Randy Johnson | Mark Knudson | Mark Knudson | Randy Johnson | | 623 | 666 | -43 |
| 1989-09-11 | vs BOS | 143 | W 2-1 | 62-81 | 6 | 14,567 | Brian Holman | John Dopson | Brian Holman | John Dopson | Mike Schooler | 625 | 667 | -42 |
| 1989-09-12 | vs BOS | 144 | W 5-3 | 63-81 | 6 | 9,690 | Scott Bankhead | Eric Hetzel | Scott Bankhead | Eric Hetzel | Mike Schooler | 630 | 670 | -40 |
| 1989-09-13 | vs BOS | 145 | W 7-4 | 64-81 | 6 | 8,837 | Clint Zavaras | Mike Boddicker | Jerry Reed | Mike Boddicker | Mike Schooler | 637 | 674 | -37 |
| 1989-09-15 | @ NYA | 146 | W 3-1 | 65-81 | 6 | 32,044 | Erik Hanson | Andy Hawkins | Erik Hanson | Andy Hawkins | | 640 | 675 | -35 |
| 1989-09-16 | @ NYA | 147 | L 1-4 | 65-82 | 6 | 22,922 | Randy Johnson | Eric Plunk | Eric Plunk | Randy Johnson | Lee Guetterman | 641 | 679 | -38 |
| 1989-09-17 | @ NYA | 148 | W 3-0 | 66-82 | 6 | 35,251 | Brian Holman | Walt Terrell | Brian Holman | Walt Terrell | Mike Schooler | 644 | 679 | -35 |
| 1989-09-18 | @ TEX | 149 | L 2-5 | 66-83 | 6 | 4,654 | Scott Bankhead | Nolan Ryan | Cecilio Guante | Michael Jackson | | 646 | 684 | -38 |
| 1989-09-19 | @ TEX | 150 | L 3-5 | 66-84 | 6 | 10,478 | Clint Zavaras | Charlie Hough | Brad Arnsberg | Jerry Reed | Jeff Russell | 649 | 689 | -40 |
| 1989-09-20 | @ TEX | 151 | L 2-3 | 66-85 | 6 | 10,684 | Erik Hanson | Mike Jeffcoat | Mike Jeffcoat | Keith Comstock | Jeff Russell | 651 | 692 | -41 |
| 1989-09-21 | @ TEX | 152 | W 8-3 | 67-85 | 6 | 10,268 | Randy Johnson | Jamie Moyer | Randy Johnson | Jamie Moyer | | 659 | 695 | -36 |
| 1989-09-22 | @ KCA | 153 | L 2-9 | 68-86 | 6 | 0 | Brian Holman | Bret Saberhagen | Bret Saberhagen | Brian Holman | | 661 | 704 | -43 |
| 1989-09-22 | @ KCA | 154 | W 2-0 | 68-86 | 6 | 29,286 | Bill Swift | Tom Gordon | Bill Swift | Tom Gordon | Mike Schooler | 663 | 704 | -41 |
| 1989-09-23 | @ KCA | 155 | W 8-0 | 69-86 | 6 | 35,102 | Scott Bankhead | Larry McWilliams | Scott Bankhead | Larry McWilliams | | 671 | 704 | -33 |
| 1989-09-24 | @ KCA | 156 | L 1-4 | 69-87 | 6 | 24,518 | Clint Zavaras | Steve Farr | Steve Farr | Clint Zavaras | Jeff Montgomery | 672 | 708 | -36 |
| 1989-09-26 | vs CLE | 157 | W 3-2 | 70-87 | 6 | 6,768 | Erik Hanson | Greg Swindell | Erik Hanson | Doug Jones | Mike Schooler | 675 | 710 | -35 |
| 1989-09-27 | vs CLE | 158 | L 1-4 | 70-88 | 6 | 6,652 | Randy Johnson | John Farrell | John Farrell | Randy Johnson | | 676 | 714 | -38 |
| 1989-09-28 | vs CLE | 159 | W 6-2 | 71-88 | 6 | 6,831 | Brian Holman | Buddy Black | Brian Holman | Steve Olin | | 682 | 716 | -34 |
| 1989-09-29 | vs MIN | 160 | L 7-10 | 71-89 | 6 | 9,916 | Scott Bankhead | Allan Anderson | Juan Berenguer | Mike Schooler | Jeff Reardon | 689 | 726 | -37 |
| 1989-09-30 | vs MIN | 161 | W 2-1 | 72-89 | 6 | 33,435 | Bill Swift | Kevin Tapani | Jerry Reed | Jeff Reardon | | 691 | 727 | -36 |
| 1989-10-01 | vs MIN | 162 | W 3-1 | 73-89 | 6 | 11,188 | Erik Hanson | Mark Guthrie | Erik Hanson | Mark Guthrie | Mike Schooler | 694 | 728 | -34 |