| 1988-04-04 | @ TEX | 1 | L 3-4 | 0-1 | 6 | 37,613 | Tom Candiotti | Charlie Hough | Charlie Hough | Chris Codiroli | Mitch Williams | 3 | 4 | -1 |
| 1988-04-06 | @ TEX | 2 | W 5-1 | 1-1 | 5 | 13,003 | Greg Swindell | Bobby Witt | Greg Swindell | Bobby Witt | | 8 | 5 | 3 |
| 1988-04-07 | @ TEX | 3 | W 4-1 | 2-1 | 3 | 12,251 | John Farrell | Jose Guzman | John Farrell | Jose Guzman | Chris Codiroli | 12 | 6 | 6 |
| 1988-04-08 | vs BAL | 4 | W 3-0 | 3-1 | 2 | 53,738 | Scott Bailes | Mark Thurmond | Scott Bailes | Mark Thurmond | | 15 | 6 | 9 |
| 1988-04-09 | vs BAL | 5 | W 12-1 | 4-1 | 2 | 16,401 | Tom Candiotti | Mike Boddicker | Tom Candiotti | Mike Boddicker | | 27 | 7 | 20 |
| 1988-04-10 | vs BAL | 6 | W 6-3 | 5-1 | 2 | 19,560 | Rich Yett | Scott McGregor | Rich Yett | Scott McGregor | Dan Schatzeder | 33 | 10 | 23 |
| 1988-04-11 | vs BAL | 7 | W 7-2 | 6-1 | 1 | 15,816 | Greg Swindell | Mike Morgan | Greg Swindell | Mike Morgan | | 40 | 12 | 28 |
| 1988-04-12 | vs MIN | 8 | L 6-7 | 6-2 | 2 | 5,084 | John Farrell | Les Straker | Joe Niekro | Chris Codiroli | Jeff Reardon | 46 | 19 | 27 |
| 1988-04-13 | vs MIN | 9 | W 6-3 | 7-2 | 2 | 6,010 | Scott Bailes | Bert Blyleven | Jeff Dedmon | Juan Berenguer | | 52 | 22 | 30 |
| 1988-04-14 | vs MIN | 10 | W 3-1 | 8-2 | 2 | 5,570 | Tom Candiotti | Charlie Lea | Tom Candiotti | Charlie Lea | | 55 | 23 | 32 |
| 1988-04-15 | @ BAL | 11 | W 3-2 | 9-2 | 2 | 13,215 | Rich Yett | Scott McGregor | Rich Yett | Scott McGregor | Doug Jones | 58 | 25 | 33 |
| 1988-04-16 | @ BAL | 12 | W 1-0 | 10-2 | 1 | 13,625 | Greg Swindell | Mike Morgan | Greg Swindell | Dave J. Schmidt | Doug Jones | 59 | 25 | 34 |
| 1988-04-17 | @ BAL | 13 | W 4-1 | 11-2 | 1 | 20,837 | John Farrell | Oswaldo Peraza | John Farrell | Oswaldo Peraza | Dan Schatzeder | 63 | 26 | 37 |
| 1988-04-19 | vs TEX | 14 | L 0-3 | 11-3 | 1 | 5,586 | Scott Bailes | Jose Guzman | Jose Guzman | Scott Bailes | Mitch Williams | 63 | 29 | 34 |
| 1988-04-20 | vs TEX | 15 | W 2-1 | 12-3 | 1 | 6,551 | Tom Candiotti | Charlie Hough | Tom Candiotti | Charlie Hough | | 65 | 30 | 35 |
| 1988-04-22 | @ MIN | 16 | W 11-6 | 13-3 | 1 | 24,466 | Greg Swindell | Bert Blyleven | Greg Swindell | Bert Blyleven | Doug Jones | 76 | 36 | 40 |
| 1988-04-23 | @ MIN | 17 | W 10-2 | 14-3 | 1 | 41,297 | John Farrell | Steve Carlton | John Farrell | Steve Carlton | | 86 | 38 | 48 |
| 1988-04-24 | @ MIN | 18 | L 7-13 | 14-4 | 1 | 46,698 | Scott Bailes | Charlie Lea | Juan Berenguer | Scott Bailes | | 93 | 51 | 42 |
| 1988-04-26 | vs SEA | 19 | W 12-6 | 15-4 | 1 | 6,690 | Tom Candiotti | Mike Moore | Tom Candiotti | Mike Moore | | 105 | 57 | 48 |
| 1988-04-27 | vs SEA | 20 | W 6-4 | 16-4 | 1 | 5,244 | Greg Swindell | Steve Trout | Greg Swindell | Steve Trout | Doug Jones | 111 | 61 | 50 |
| 1988-04-28 | vs SEA | 21 | L 1-3 | 16-5 | 1 | 3,762 | John Farrell | Mike Campbell | Mike Campbell | John Farrell | | 112 | 64 | 48 |
| 1988-04-30 | vs OAK | 22 | L 3-11 | 16-6 | 1 | 25,222 | Rich Yett | Bob Welch | Bob Welch | Rich Yett | Gene Nelson | 115 | 75 | 40 |
| 1988-05-01 | vs OAK | 23 | L 4-8 | 16-7 | 1 | 29,126 | Tom Candiotti | Storm Davis | Eric Plunk | Doug Jones | | 119 | 83 | 36 |
| 1988-05-02 | vs CAL | 24 | W 3-0 | 17-7 | 1 | 8,121 | Greg Swindell | Willie Fraser | Greg Swindell | Willie Fraser | | 122 | 83 | 39 |
| 1988-05-03 | vs CAL | 25 | L 4-8 | 17-8 | 2 | 6,912 | John Farrell | Kirk McCaskill | Donnie Moore | Dan Schatzeder | | 126 | 91 | 35 |
| 1988-05-04 | @ SEA | 26 | L 4-5 | 17-9 | 2 | 7,213 | Scott Bailes | Mark Langston | Mark Langston | Scott Bailes | Julio Solano | 130 | 96 | 34 |
| 1988-05-05 | @ SEA | 27 | L 2-7 | 17-10 | 2 | 6,590 | Rich Yett | Bill Swift | Bill Swift | Rich Yett | | 132 | 103 | 29 |
| 1988-05-07 | @ OAK | 28 | L 3-14 | 17-11 | 2 | 22,793 | Tom Candiotti | Storm Davis | Storm Davis | Tom Candiotti | Gene Nelson | 135 | 117 | 18 |
| 1988-05-08 | @ OAK | 29 | L 1-5 | 17-12 | 4 | 31,829 | Greg Swindell | Dave Stewart | Dave Stewart | Greg Swindell | | 136 | 122 | 14 |
| 1988-05-09 | @ CAL | 30 | L 1-2 | 17-13 | 5 | 22,123 | John Farrell | Dan Petry | Dan Petry | John Farrell | Bryan Harvey | 137 | 124 | 13 |
| 1988-05-10 | @ CAL | 31 | W 7-1 | 18-13 | 4 | 22,519 | Scott Bailes | Chuck Finley | Scott Bailes | Chuck Finley | | 144 | 125 | 19 |
| 1988-05-11 | @ CAL | 32 | W 4-3 | 19-13 | 3 | 23,713 | Rich Yett | Mike Witt | Doug Jones | Bryan Harvey | | 148 | 128 | 20 |
| 1988-05-12 | @ MIL | 33 | W 3-1 | 20-13 | 3 | 10,148 | Tom Candiotti | Juan Nieves | Tom Candiotti | Chuck Crim | | 151 | 129 | 22 |
| 1988-05-13 | @ MIL | 34 | W 4-3 | 21-13 | 3 | 17,827 | Greg Swindell | Teddy Higuera | Greg Swindell | Teddy Higuera | Doug Jones | 155 | 132 | 23 |
| 1988-05-14 | @ MIL | 35 | W 6-4 | 22-13 | 2 | 40,954 | John Farrell | Mike Birkbeck | John Farrell | Mike Birkbeck | Bill Laskey | 161 | 136 | 25 |
| 1988-05-15 | @ MIL | 36 | L 5-9 | 22-14 | 2 | 17,511 | Scott Bailes | Bill Wegman | Bill Wegman | Scott Bailes | Paul Mirabella | 166 | 145 | 21 |
| 1988-05-17 | vs CHA | 37 | W 6-2 | 23-14 | 2 | 9,499 | Rich Yett | Jack McDowell | Rich Yett | Jack McDowell | Doug Jones | 172 | 147 | 25 |
| 1988-05-18 | vs CHA | 38 | W 2-1 | 24-14 | 2 | 8,299 | Tom Candiotti | Melido Perez | Tom Candiotti | Melido Perez | | 174 | 148 | 26 |
| 1988-05-19 | vs CHA | 39 | W 1-0 | 25-14 | 2 | 10,197 | Greg Swindell | Dave LaPoint | Greg Swindell | Bobby Thigpen | | 175 | 148 | 27 |
| 1988-05-20 | @ KCA | 40 | L 3-4 | 25-15 | 2 | 25,528 | John Farrell | Mark Gubicza | Mark Gubicza | John Farrell | Steve Farr | 178 | 152 | 26 |
| 1988-05-21 | @ KCA | 41 | W 9-5 | 26-15 | 2 | 35,941 | Scott Bailes | Floyd Bannister | Scott Bailes | Floyd Bannister | Doug Jones | 187 | 157 | 30 |
| 1988-05-22 | @ KCA | 42 | W 8-7 | 27-15 | 2 | 33,936 | Rich Yett | Ted Power | Bill Laskey | Gene Garber | Doug Jones | 195 | 164 | 31 |
| 1988-05-23 | @ CHA | 43 | L 2-3 | 27-16 | 3 | 8,624 | Tom Candiotti | Melido Perez | Melido Perez | Tom Candiotti | Bobby Thigpen | 197 | 167 | 30 |
| 1988-05-24 | @ CHA | 44 | W 4-3 | 28-16 | 2 | 8,956 | Greg Swindell | Dave LaPoint | Greg Swindell | Dave LaPoint | Doug Jones | 201 | 170 | 31 |
| 1988-05-25 | @ CHA | 45 | W 5-2 | 29-16 | 2 | 9,900 | John Farrell | John Davis | John Farrell | John Davis | | 206 | 172 | 34 |
| 1988-05-27 | vs MIL | 46 | W 6-3 | 30-16 | 2 | 37,658 | Scott Bailes | Mike Birkbeck | Scott Bailes | Mike Birkbeck | Doug Jones | 212 | 175 | 37 |
| 1988-05-28 | vs MIL | 47 | L 0-2 | 30-17 | 2 | 38,374 | Rich Yett | Odell Jones | Odell Jones | Rich Yett | Dan Plesac | 212 | 177 | 35 |
| 1988-05-29 | vs MIL | 48 | L 2-7 | 30-18 | 2 | 27,508 | Tom Candiotti | Tom Filer | Tom Filer | Tom Candiotti | | 214 | 184 | 30 |
| 1988-05-30 | vs KCA | 49 | W 4-1 | 31-18 | 2 | 33,533 | Greg Swindell | Charlie Leibrandt | Greg Swindell | Charlie Leibrandt | Doug Jones | 218 | 185 | 33 |
| 1988-05-31 | vs KCA | 50 | L 3-6 | 31-19 | 2 | 8,978 | John Farrell | Mark Gubicza | Mark Gubicza | Dan Schatzeder | Steve Farr | 221 | 191 | 30 |
| 1988-06-01 | vs KCA | 51 | W 5-4 | 32-19 | 2 | 8,732 | Scott Bailes | Floyd Bannister | Scott Bailes | Floyd Bannister | Doug Jones | 226 | 195 | 31 |
| 1988-06-03 | @ DET | 52 | W 6-3 | 33-19 | 2 | 25,230 | Rich Yett | Walt Terrell | Rich Yett | Walt Terrell | Dan Schatzeder | 232 | 198 | 34 |
| 1988-06-04 | @ DET | 53 | L 2-5 | 33-20 | 2 | 32,391 | Tom Candiotti | Doyle Alexander | Doyle Alexander | Tom Candiotti | | 234 | 203 | 31 |
| 1988-06-05 | @ DET | 54 | L 2-6 | 33-21 | 2 | 31,665 | Greg Swindell | Jeff Robinson | Jeff Robinson | Greg Swindell | | 236 | 209 | 27 |
| 1988-06-06 | vs TOR | 55 | W 6-3 | 34-21 | 2 | 9,550 | John Farrell | Mike Flanagan | John Farrell | Mike Flanagan | Doug Jones | 242 | 212 | 30 |
| 1988-06-07 | vs TOR | 56 | W 5-3 | 35-21 | 2 | 21,696 | Scott Bailes | Todd Stottlemyre | Scott Bailes | David Wells | | 247 | 215 | 32 |
| 1988-06-08 | vs TOR | 57 | W 4-2 | 36-21 | 2 | 10,571 | Rich Yett | Jim Clancy | Rich Yett | Jim Clancy | Doug Jones | 251 | 217 | 34 |
| 1988-06-09 | vs DET | 58 | L 2-6 | 36-22 | 2 | 17,375 | Tom Candiotti | Doyle Alexander | Mike Henneman | Tom Candiotti | | 253 | 223 | 30 |
| 1988-06-10 | vs DET | 59 | L 1-2 | 36-23 | 2 | 71,188 | Greg Swindell | Jeff Robinson | Jeff Robinson | Greg Swindell | Mike Henneman | 254 | 225 | 29 |
| 1988-06-11 | vs DET | 60 | L 3-11 | 36-24 | 3 | 26,978 | John Farrell | Jack Morris | Jack Morris | John Farrell | | 257 | 236 | 21 |
| 1988-06-12 | vs DET | 61 | L 4-5 | 36-25 | 3 | 41,345 | Scott Bailes | Frank Tanana | Frank Tanana | Scott Bailes | Mike Henneman | 261 | 241 | 20 |
| 1988-06-13 | @ TOR | 62 | W 8-6 | 37-25 | 3 | 31,133 | Rich Yett | Jim Clancy | Buddy Black | Jim Clancy | Doug Jones | 269 | 247 | 22 |
| 1988-06-14 | @ TOR | 63 | L 2-3 | 37-26 | 3 | 31,433 | Tom Candiotti | Todd Stottlemyre | Duane Ward | Tom Candiotti | | 271 | 250 | 21 |
| 1988-06-15 | @ TOR | 64 | L 3-15 | 37-27 | 3 | 45,472 | Greg Swindell | Dave Stieb | Dave Stieb | Greg Swindell | | 274 | 265 | 9 |
| 1988-06-17 | vs NYA | 65 | W 6-4 | 38-27 | 3 | 56,485 | John Farrell | John Candelaria | John Farrell | John Candelaria | Doug Jones | 280 | 269 | 11 |
| 1988-06-18 | vs NYA | 66 | L 3-6 | 38-28 | 3 | 48,936 | Scott Bailes | Rick Rhoden | Rick Rhoden | Scott Bailes | Cecilio Guante | 283 | 275 | 8 |
| 1988-06-19 | vs NYA | 67 | W 11-3 | 39-28 | 3 | 49,912 | Tom Candiotti | Richard Dotson | Tom Candiotti | Richard Dotson | | 294 | 278 | 16 |
| 1988-06-20 | vs BOS | 68 | L 7-14 | 39-29 | 3 | 19,870 | Greg Swindell | Bruce Hurst | Bruce Hurst | Greg Swindell | | 301 | 292 | 9 |
| 1988-06-21 | vs BOS | 69 | L 6-10 | 39-30 | 3 | 26,681 | Rick Rodriguez | Jeff Sellers | Bob Stanley | Rick Rodriguez | Lee Smith | 307 | 302 | 5 |
| 1988-06-22 | vs BOS | 70 | W 3-1 | 40-30 | 3 | 18,843 | John Farrell | Oil Can Boyd | John Farrell | Oil Can Boyd | Doug Jones | 310 | 303 | 7 |
| 1988-06-23 | @ NYA | 71 | L 3-4 | 40-31 | 3 | 31,341 | Scott Bailes | Rick Rhoden | Dave Righetti | Jon Perlman | | 313 | 307 | 6 |
| 1988-06-24 | @ NYA | 72 | W 7-5 | 41-31 | 3 | 38,049 | Tom Candiotti | Richard Dotson | Brad Havens | Richard Dotson | Doug Jones | 320 | 312 | 8 |
| 1988-06-25 | @ NYA | 73 | L 1-4 | 41-32 | 3 | 38,202 | Greg Swindell | Tommy John | Tommy John | Greg Swindell | Cecilio Guante | 321 | 316 | 5 |
| 1988-06-26 | @ NYA | 74 | L 3-4 | 41-33 | 3 | 53,037 | Rick Rodriguez | Charles Hudson | Dave Righetti | Buddy Black | | 324 | 320 | 4 |
| 1988-06-27 | @ BOS | 75 | L 5-9 | 41-34 | 3 | 33,318 | John Farrell | Oil Can Boyd | Dennis Lamp | John Farrell | | 329 | 329 | 0 |
| 1988-06-28 | @ BOS | 76 | L 1-6 | 41-35 | 3 | 34,661 | Scott Bailes | Wes Gardner | Wes Gardner | Scott Bailes | | 330 | 335 | -5 |
| 1988-06-29 | @ BOS | 77 | L 1-5 | 41-36 | 4 | 35,035 | Tom Candiotti | Roger Clemens | Roger Clemens | Tom Candiotti | Lee Smith | 331 | 340 | -9 |
| 1988-07-01 | vs SEA | 78 | L 3-11 | 41-37 | 4 | 45,785 | Greg Swindell | Mark Langston | Mark Langston | Greg Swindell | Michael Jackson | 334 | 351 | -17 |
| 1988-07-02 | vs SEA | 79 | W 10-7 | 42-37 | 3 | 18,096 | John Farrell | Bill Swift | John Farrell | Bill Swift | Doug Jones | 344 | 358 | -14 |
| 1988-07-03 | vs SEA | 80 | L 6-7 | 42-38 | 3 | 19,397 | Buddy Black | Scott Bankhead | Scott Bankhead | Jon Perlman | Mike Schooler | 350 | 365 | -15 |
| 1988-07-04 | vs OAK | 81 | L 2-4 | 42-39 | 4 | 20,891 | Tom Candiotti | Bob Welch | Greg Cadaret | Brad Havens | Dennis Eckersley | 352 | 369 | -17 |
| 1988-07-05 | vs OAK | 82 | W 3-0 | 44-39 | 3 | 0 | Scott Bailes | Dave Stewart | Scott Bailes | Dave Stewart | | 355 | 369 | -14 |
| 1988-07-05 | vs OAK | 83 | W 4-2 | 44-39 | 3 | 17,983 | Rick Rodriguez | Rich Bordi | Rick Rodriguez | Rich Bordi | Doug Jones | 359 | 371 | -12 |
| 1988-07-06 | vs OAK | 84 | W 8-6 | 45-39 | 3 | 16,317 | Greg Swindell | Todd Burns | Don Gordon | Rick Honeycutt | | 367 | 377 | -10 |
| 1988-07-07 | vs CAL | 85 | L 1-7 | 45-40 | 3 | 10,889 | John Farrell | Terry Clark | Terry Clark | John Farrell | Greg Minton | 368 | 384 | -16 |
| 1988-07-08 | vs CAL | 86 | L 6-10 | 45-41 | 3 | 19,588 | Buddy Black | Kirk McCaskill | Kirk McCaskill | Buddy Black | Bryan Harvey | 374 | 394 | -20 |
| 1988-07-09 | vs CAL | 87 | L 5-8 | 45-42 | 3 | 15,487 | Tom Candiotti | Mike Witt | Bryan Harvey | Doug Jones | Donnie Moore | 379 | 402 | -23 |
| 1988-07-10 | vs CAL | 88 | L 5-7 | 45-43 | 3 | 20,050 | Scott Bailes | Willie Fraser | Willie Fraser | Scott Bailes | Greg Minton | 384 | 409 | -25 |
| 1988-07-14 | @ SEA | 89 | L 1-3 | 45-44 | 5 | 9,277 | Greg Swindell | Mark Langston | Mark Langston | Greg Swindell | | 385 | 412 | -27 |
| 1988-07-15 | @ SEA | 90 | L 5-8 | 45-45 | 5 | 9,593 | John Farrell | Mike Moore | Michael Jackson | Brad Havens | Mike Schooler | 390 | 420 | -30 |
| 1988-07-16 | @ SEA | 91 | W 8-2 | 46-45 | 5 | 17,761 | Buddy Black | Scott Bankhead | Buddy Black | Scott Bankhead | Doug Jones | 398 | 422 | -24 |
| 1988-07-17 | @ SEA | 92 | W 7-4 | 47-45 | 5 | 9,779 | Tom Candiotti | Bill Swift | Don Gordon | Bill Swift | Doug Jones | 405 | 426 | -21 |
| 1988-07-18 | @ OAK | 93 | L 2-7 | 47-46 | 5 | 27,849 | Scott Bailes | Todd Burns | Todd Burns | Scott Bailes | | 407 | 433 | -26 |
| 1988-07-19 | @ OAK | 94 | L 2-4 | 47-48 | 6 | 0 | Greg Swindell | Bob Welch | Bob Welch | Greg Swindell | Dennis Eckersley | 409 | 437 | -28 |
| 1988-07-19 | @ OAK | 95 | L 6-9 | 47-48 | 6 | 17,299 | Rick Rodriguez | Rich Bordi | Greg Cadaret | Don Gordon | Dennis Eckersley | 415 | 446 | -31 |
| 1988-07-20 | @ OAK | 96 | W 5-4 | 48-48 | 5 | 27,439 | John Farrell | Dave Stewart | John Farrell | Dave Stewart | Doug Jones | 420 | 450 | -30 |
| 1988-07-22 | @ CAL | 97 | L 4-7 | 48-49 | 5 | 27,403 | Tom Candiotti | Terry Clark | Terry Clark | Tom Candiotti | | 424 | 457 | -33 |
| 1988-07-23 | @ CAL | 98 | L 4-5 | 48-50 | 5 | 34,977 | Scott Bailes | Chuck Finley | Stew Cliburn | Don Gordon | Greg Minton | 428 | 462 | -34 |
| 1988-07-24 | @ CAL | 99 | W 9-2 | 49-50 | 5 | 31,015 | Greg Swindell | Willie Fraser | Greg Swindell | Willie Fraser | | 437 | 464 | -27 |
| 1988-07-26 | vs BAL | 100 | W 7-3 | 50-50 | 5 | 17,864 | John Farrell | Jay Tibbs | John Farrell | Jay Tibbs | Doug Jones | 444 | 467 | -23 |
| 1988-07-27 | vs BAL | 101 | W 12-2 | 51-50 | 4 | 20,445 | Tom Candiotti | Jose Bautista | Tom Candiotti | Jose Bautista | | 456 | 469 | -13 |
| 1988-07-28 | vs BAL | 102 | L 2-5 | 51-51 | 5 | 14,808 | Scott Bailes | Oswaldo Peraza | Oswaldo Peraza | Scott Bailes | Tom Niedenfuer | 458 | 474 | -16 |
| 1988-07-29 | vs MIN | 103 | W 7-0 | 52-51 | 4 | 20,179 | Greg Swindell | Bert Blyleven | Greg Swindell | Bert Blyleven | | 465 | 474 | -9 |
| 1988-07-30 | vs MIN | 104 | L 2-4 | 52-52 | 4 | 22,733 | Rod Nichols | Allan Anderson | Allan Anderson | Rod Nichols | | 467 | 478 | -11 |
| 1988-07-31 | vs MIN | 105 | L 4-12 | 52-53 | 4 | 24,045 | John Farrell | Freddie Toliver | Freddie Toliver | John Farrell | Mark Portugal | 471 | 490 | -19 |
| 1988-08-02 | @ BAL | 106 | L 2-5 | 52-54 | 6 | 15,983 | Scott Bailes | Oswaldo Peraza | Oswaldo Peraza | Scott Bailes | | 473 | 495 | -22 |
| 1988-08-03 | @ BAL | 107 | L 3-8 | 52-55 | 6 | 15,546 | Rick Rodriguez | Jeff Ballard | Jeff Ballard | Rick Rodriguez | | 476 | 503 | -27 |
| 1988-08-04 | @ BAL | 108 | L 0-5 | 52-56 | 6 | 21,543 | Greg Swindell | Dave J. Schmidt | Dave J. Schmidt | Greg Swindell | | 476 | 508 | -32 |
| 1988-08-05 | @ TEX | 109 | L 4-8 | 52-57 | 6 | 21,527 | Rod Nichols | Paul Kilgus | Paul Kilgus | Rod Nichols | Craig McMurtry | 480 | 516 | -36 |
| 1988-08-06 | @ TEX | 110 | W 5-3 | 53-57 | 6 | 31,003 | John Farrell | Charlie Hough | John Farrell | Charlie Hough | Doug Jones | 485 | 519 | -34 |
| 1988-08-07 | @ TEX | 111 | L 0-2 | 53-58 | 6 | 17,089 | Rich Yett | Jose Guzman | Jose Guzman | Rich Yett | | 485 | 521 | -36 |
| 1988-08-08 | @ MIN | 112 | L 2-7 | 53-59 | 6 | 36,316 | Chris Codiroli | Allan Anderson | Allan Anderson | Chris Codiroli | Jeff Reardon | 487 | 528 | -41 |
| 1988-08-09 | @ MIN | 113 | L 3-4 | 53-60 | 6 | 37,880 | Greg Swindell | Freddie Toliver | Freddie Toliver | Greg Swindell | Jeff Reardon | 490 | 532 | -42 |
| 1988-08-10 | @ MIN | 114 | L 4-10 | 53-61 | 6 | 43,480 | Rod Nichols | Frank Viola | Frank Viola | Rod Nichols | | 494 | 542 | -48 |
| 1988-08-11 | vs TEX | 115 | L 4-5 | 53-62 | 6 | 10,703 | John Farrell | Charlie Hough | Mitch Williams | Doug Jones | Dale Mohorcic | 498 | 547 | -49 |
| 1988-08-12 | vs TEX | 116 | W 6-3 | 54-62 | 6 | 20,754 | Rich Yett | Jose Guzman | Rich Yett | Jose Guzman | Don Gordon | 504 | 550 | -46 |
| 1988-08-13 | vs TEX | 117 | L 3-12 | 54-63 | 6 | 11,069 | Chris Codiroli | Jeff Russell | Jeff Russell | Chris Codiroli | | 507 | 562 | -55 |
| 1988-08-14 | vs TEX | 118 | W 3-0 | 55-63 | 6 | 19,628 | Greg Swindell | Bobby Witt | Greg Swindell | Bobby Witt | Doug Jones | 510 | 562 | -52 |
| 1988-08-16 | vs MIL | 119 | W 6-5 | 56-63 | 6 | 12,394 | Rod Nichols | Don August | Scott Bailes | Chuck Crim | | 516 | 567 | -51 |
| 1988-08-17 | vs MIL | 120 | W 11-7 | 57-63 | 6 | 7,593 | John Farrell | Mike Birkbeck | John Farrell | Mike Birkbeck | | 527 | 574 | -47 |
| 1988-08-18 | vs MIL | 121 | W 4-3 | 58-63 | 6 | 6,732 | Rich Yett | Bill Wegman | Rich Yett | Bill Wegman | Doug Jones | 531 | 577 | -46 |
| 1988-08-19 | vs KCA | 122 | W 4-2 | 59-63 | 6 | 13,098 | Tom Candiotti | Bret Saberhagen | Tom Candiotti | Bret Saberhagen | Doug Jones | 535 | 579 | -44 |
| 1988-08-20 | vs KCA | 123 | L 2-4 | 59-64 | 6 | 17,047 | Greg Swindell | Charlie Leibrandt | Charlie Leibrandt | Greg Swindell | Steve Farr | 537 | 583 | -46 |
| 1988-08-21 | vs KCA | 124 | L 1-3 | 59-65 | 6 | 17,949 | Buddy Black | Mark Gubicza | Mark Gubicza | Rod Nichols | | 538 | 586 | -48 |
| 1988-08-22 | @ MIL | 125 | L 3-7 | 59-66 | 6 | 16,801 | John Farrell | Mike Birkbeck | Mike Birkbeck | John Farrell | Chuck Crim | 541 | 593 | -52 |
| 1988-08-23 | @ MIL | 126 | W 6-2 | 60-66 | 6 | 16,499 | Rich Yett | Bill Wegman | Rich Yett | Bill Wegman | | 547 | 595 | -48 |
| 1988-08-24 | @ MIL | 127 | W 7-2 | 61-66 | 6 | 16,322 | Tom Candiotti | Tom Filer | Tom Candiotti | Tom Filer | Doug Jones | 554 | 597 | -43 |
| 1988-08-26 | @ CHA | 128 | W 7-6 | 62-66 | 6 | 13,334 | Greg Swindell | Jack McDowell | Greg Swindell | Jack McDowell | Doug Jones | 561 | 603 | -42 |
| 1988-08-27 | @ CHA | 129 | L 1-4 | 62-67 | 6 | 18,056 | John Farrell | Jerry Reuss | Jerry Reuss | John Farrell | | 562 | 607 | -45 |
| 1988-08-28 | @ CHA | 130 | W 5-4 | 63-67 | 6 | 18,091 | Buddy Black | Melido Perez | Doug Jones | Barry Jones | | 567 | 611 | -44 |
| 1988-08-29 | @ KCA | 131 | L 3-6 | 63-68 | 6 | 29,002 | Rich Yett | Bret Saberhagen | Bret Saberhagen | Scott Bailes | Steve Farr | 570 | 617 | -47 |
| 1988-08-30 | @ KCA | 132 | W 4-1 | 64-68 | 6 | 23,437 | Tom Candiotti | Ted Power | Tom Candiotti | Ted Power | Brad Havens | 574 | 618 | -44 |
| 1988-08-31 | @ KCA | 133 | L 0-1 | 64-69 | 6 | 20,615 | Greg Swindell | Charlie Leibrandt | Charlie Leibrandt | Greg Swindell | | 574 | 619 | -45 |
| 1988-09-02 | vs CHA | 134 | W 4-3 | 65-69 | 6 | 8,859 | Rod Nichols | Jerry Reuss | Doug Jones | Ken Patterson | | 578 | 622 | -44 |
| 1988-09-04 | vs CHA | 135 | W 3-2 | 66-70 | 6 | 0 | Buddy Black | Melido Perez | Brad Havens | Barry Jones | | 581 | 624 | -43 |
| 1988-09-04 | vs CHA | 136 | L 2-5 | 66-70 | 6 | 11,979 | Rich Yett | Bill Long | Bill Long | Doug Jones | Bobby Thigpen | 583 | 629 | -46 |
| 1988-09-05 | @ NYA | 137 | L 2-7 | 66-71 | 6 | 27,884 | Tom Candiotti | Rick Rhoden | Rick Rhoden | Don Gordon | | 585 | 636 | -51 |
| 1988-09-06 | @ NYA | 138 | W 1-0 | 67-71 | 6 | 22,055 | Greg Swindell | Al Leiter | Greg Swindell | Al Leiter | | 586 | 636 | -50 |
| 1988-09-07 | @ NYA | 139 | W 5-4 | 68-71 | 6 | 30,023 | Rod Nichols | Tommy John | Rod Nichols | Tommy John | Doug Jones | 591 | 640 | -49 |
| 1988-09-09 | @ BOS | 140 | L 4-7 | 68-72 | 6 | 33,349 | Rich Yett | Mike Boddicker | Mike Boddicker | Rich Yett | Lee Smith | 595 | 647 | -52 |
| 1988-09-10 | @ BOS | 141 | L 0-6 | 68-73 | 6 | 34,099 | Buddy Black | Roger Clemens | Roger Clemens | Buddy Black | | 595 | 653 | -58 |
| 1988-09-11 | @ BOS | 142 | W 4-2 | 69-73 | 6 | 33,154 | Tom Candiotti | Wes Gardner | Tom Candiotti | Bob Stanley | Doug Jones | 599 | 655 | -56 |
| 1988-09-12 | vs NYA | 143 | W 8-6 | 70-73 | 6 | 11,426 | Greg Swindell | Tommy John | Greg Swindell | Tommy John | Doug Jones | 607 | 661 | -54 |
| 1988-09-13 | vs NYA | 144 | L 4-5 | 70-74 | 6 | 8,455 | Rod Nichols | Ron Guidry | Neil Allen | Scott Bailes | Dave Righetti | 611 | 666 | -55 |
| 1988-09-14 | vs NYA | 145 | L 5-7 | 70-75 | 6 | 12,478 | Rich Yett | Richard Dotson | Richard Dotson | Rich Yett | Dale Mohorcic | 616 | 673 | -57 |
| 1988-09-15 | @ TOR | 146 | L 0-3 | 70-76 | 6 | 28,544 | Mike Walker | Jeff Musselman | Jeff Musselman | Mike Walker | Tom Henke | 616 | 676 | -60 |
| 1988-09-16 | @ TOR | 147 | L 3-4 | 70-77 | 6 | 30,276 | Tom Candiotti | Mike Flanagan | Tom Henke | Don Gordon | | 619 | 680 | -61 |
| 1988-09-17 | @ TOR | 148 | W 12-3 | 71-77 | 6 | 32,067 | Greg Swindell | Jimmy Key | Greg Swindell | Jimmy Key | Jeff Dedmon | 631 | 683 | -52 |
| 1988-09-18 | @ TOR | 149 | L 0-4 | 71-78 | 6 | 34,422 | Rod Nichols | Dave Stieb | Dave Stieb | Rod Nichols | | 631 | 687 | -56 |
| 1988-09-19 | @ DET | 150 | W 4-3 | 72-78 | 6 | 15,383 | Rich Yett | Walt Terrell | Don Gordon | Mike Henneman | Doug Jones | 635 | 690 | -55 |
| 1988-09-20 | @ DET | 151 | L 1-3 | 72-79 | 6 | 14,593 | John Farrell | Jack Morris | Jack Morris | Scott Bailes | | 636 | 693 | -57 |
| 1988-09-21 | @ DET | 152 | L 2-3 | 72-80 | 6 | 14,707 | Tom Candiotti | Doyle Alexander | Doyle Alexander | Brad Havens | Eric King | 638 | 696 | -58 |
| 1988-09-23 | vs TOR | 153 | L 2-4 | 72-81 | 6 | 7,995 | Greg Swindell | Jimmy Key | Jimmy Key | Greg Swindell | Tom Henke | 640 | 700 | -60 |
| 1988-09-24 | vs TOR | 154 | L 0-1 | 72-82 | 6 | 8,157 | Rod Nichols | Dave Stieb | Dave Stieb | Rod Nichols | | 640 | 701 | -61 |
| 1988-09-25 | vs TOR | 155 | W 4-3 | 73-82 | 6 | 7,915 | Rich Yett | Jim Clancy | Scott Bailes | Duane Ward | | 644 | 704 | -60 |
| 1988-09-26 | vs DET | 156 | L 3-6 | 73-83 | 6 | 4,709 | John Farrell | Eric King | Eric King | John Farrell | Mike Henneman | 647 | 710 | -63 |
| 1988-09-27 | vs DET | 157 | W 4-0 | 74-83 | 6 | 4,626 | Tom Candiotti | Frank Tanana | Tom Candiotti | Frank Tanana | | 651 | 710 | -59 |
| 1988-09-28 | vs DET | 158 | W 4-2 | 75-83 | 6 | 5,262 | Greg Swindell | Walt Terrell | Greg Swindell | Walt Terrell | Doug Jones | 655 | 712 | -57 |
| 1988-09-29 | vs BOS | 159 | L 0-12 | 75-84 | 6 | 5,879 | Rod Nichols | Mike Boddicker | Mike Boddicker | Rod Nichols | | 655 | 724 | -69 |
| 1988-09-30 | vs BOS | 160 | W 4-2 | 76-84 | 6 | 15,497 | Rich Yett | Roger Clemens | Rich Yett | Roger Clemens | Doug Jones | 659 | 726 | -67 |
| 1988-10-01 | vs BOS | 161 | W 1-0 | 77-84 | 6 | 14,972 | John Farrell | Jeff Sellers | John Farrell | Jeff Sellers | Doug Jones | 660 | 726 | -66 |
| 1988-10-02 | vs BOS | 162 | W 6-5 | 78-84 | 6 | 10,456 | Tom Candiotti | Mike Boddicker | Tom Candiotti | Dennis Lamp | Buddy Black | 666 | 731 | -65 |