| 1988-04-04 | vs SEA | 1 | W 4-1 | 1-0 | 2 | 45,333 | Dave Stewart | Mark Langston | Dave Stewart | Mark Langston | Dennis Eckersley | 4 | 1 | 3 |
| 1988-04-05 | vs SEA | 2 | W 6-0 | 2-0 | 2 | 14,005 | Bob Welch | Mike Moore | Bob Welch | Mike Moore | Dennis Eckersley | 10 | 1 | 9 |
| 1988-04-06 | vs SEA | 3 | L 5-6 | 2-1 | 1 | 18,536 | Curt Young | Steve Trout | Bill Swift | Gene Nelson | Julio Solano | 15 | 7 | 8 |
| 1988-04-08 | @ CAL | 4 | W 8-2 | 3-1 | 2 | 45,586 | Storm Davis | Kirk McCaskill | Storm Davis | Kirk McCaskill | Eric Plunk | 23 | 9 | 14 |
| 1988-04-09 | @ CAL | 5 | W 8-6 | 4-1 | 1 | 44,314 | Dave Stewart | Mike Witt | Dave Stewart | Donnie Moore | Dennis Eckersley | 31 | 15 | 16 |
| 1988-04-10 | @ CAL | 6 | L 4-6 | 4-2 | 1 | 31,297 | Bob Welch | Willie Fraser | Willie Fraser | Bob Welch | DeWayne Buice | 35 | 21 | 14 |
| 1988-04-12 | @ SEA | 7 | L 4-6 | 4-3 | 2 | 35,321 | Gene Nelson | Steve Trout | Steve Trout | Gene Nelson | Jerry Reed | 39 | 27 | 12 |
| 1988-04-13 | @ SEA | 8 | W 12-7 | 5-3 | 2 | 17,032 | Steve Ontiveros | Mike Campbell | Steve Ontiveros | Mike Campbell | Rick Honeycutt | 51 | 34 | 17 |
| 1988-04-14 | @ SEA | 9 | W 5-4 | 6-3 | 2 | 10,071 | Dave Stewart | Mark Langston | Dave Stewart | Jerry Reed | Dennis Eckersley | 56 | 38 | 18 |
| 1988-04-15 | vs CHA | 10 | L 3-11 | 6-4 | 2 | 16,237 | Bob Welch | Ricky Horton | Ricky Horton | Bob Welch | | 59 | 49 | 10 |
| 1988-04-16 | vs CHA | 11 | L 1-5 | 6-5 | 2 | 30,087 | Storm Davis | Melido Perez | Melido Perez | Storm Davis | Bobby Thigpen | 60 | 54 | 6 |
| 1988-04-17 | vs CHA | 12 | L 6-7 | 6-6 | 4 | 45,150 | Steve Ontiveros | Jack McDowell | Jack McDowell | Steve Ontiveros | Bobby Thigpen | 66 | 61 | 5 |
| 1988-04-18 | vs CAL | 13 | W 5-4 | 7-6 | 2 | 20,644 | Curt Young | Dan Petry | Eric Plunk | DeWayne Buice | Dennis Eckersley | 71 | 65 | 6 |
| 1988-04-19 | vs CAL | 14 | W 8-3 | 8-6 | 2 | 8,183 | Dave Stewart | Chuck Finley | Dave Stewart | Chuck Finley | Dennis Eckersley | 79 | 68 | 11 |
| 1988-04-20 | vs CAL | 15 | W 9-8 | 9-6 | 1 | 14,299 | Bob Welch | Mike Witt | Gene Nelson | Donnie Moore | | 88 | 76 | 12 |
| 1988-04-21 | @ CHA | 16 | W 6-3 | 10-6 | 1 | 7,039 | Storm Davis | Melido Perez | Gene Nelson | Bill Long | Dennis Eckersley | 94 | 79 | 15 |
| 1988-04-22 | @ CHA | 17 | L 5-7 | 10-7 | 1 | 7,230 | Steve Ontiveros | Jack McDowell | John Pawlowski | Eric Plunk | | 99 | 86 | 13 |
| 1988-04-23 | @ CHA | 18 | W 3-2 | 11-7 | 1 | 12,224 | Dave Stewart | Dave LaPoint | Dave Stewart | John Davis | | 102 | 88 | 14 |
| 1988-04-24 | @ CHA | 19 | W 5-3 | 12-7 | 1 | 14,221 | Bob Welch | Ricky Horton | Bob Welch | Ricky Horton | Dennis Eckersley | 107 | 91 | 16 |
| 1988-04-26 | @ TOR | 20 | W 6-1 | 13-7 | 1 | 21,280 | Storm Davis | Dave Stieb | Storm Davis | Dave Stieb | Dennis Eckersley | 113 | 92 | 21 |
| 1988-04-27 | @ TOR | 21 | W 5-3 | 14-7 | 1 | 20,236 | Curt Young | Mike Flanagan | Curt Young | Mike Flanagan | Rick Honeycutt | 118 | 95 | 23 |
| 1988-04-28 | @ TOR | 22 | W 6-2 | 15-7 | 1 | 21,178 | Dave Stewart | Todd Stottlemyre | Dave Stewart | Todd Stottlemyre | Rick Honeycutt | 124 | 97 | 27 |
| 1988-04-30 | @ CLE | 23 | W 11-3 | 16-7 | 1 | 25,222 | Bob Welch | Rich Yett | Bob Welch | Rich Yett | Gene Nelson | 135 | 100 | 35 |
| 1988-05-01 | @ CLE | 24 | W 8-4 | 17-7 | 1 | 29,126 | Storm Davis | Tom Candiotti | Eric Plunk | Doug Jones | | 143 | 104 | 39 |
| 1988-05-02 | @ DET | 25 | W 4-2 | 18-7 | 1 | 15,856 | Curt Young | Doyle Alexander | Curt Young | Mike Henneman | Dennis Eckersley | 147 | 106 | 41 |
| 1988-05-03 | @ DET | 26 | W 8-2 | 19-7 | 1 | 20,221 | Dave Stewart | Frank Tanana | Dave Stewart | Frank Tanana | | 155 | 108 | 47 |
| 1988-05-04 | vs TOR | 27 | W 3-2 | 20-7 | 1 | 21,401 | Bob Welch | Jim Clancy | Bob Welch | Jim Clancy | Dennis Eckersley | 158 | 110 | 48 |
| 1988-05-05 | vs TOR | 28 | W 8-5 | 21-7 | 1 | 16,998 | Steve Ontiveros | John Cerutti | Eric Plunk | Jose Nunez | | 166 | 115 | 51 |
| 1988-05-07 | vs CLE | 29 | W 14-3 | 22-7 | 1 | 22,793 | Storm Davis | Tom Candiotti | Storm Davis | Tom Candiotti | Gene Nelson | 180 | 118 | 62 |
| 1988-05-08 | vs CLE | 30 | W 5-1 | 23-7 | 1 | 31,829 | Dave Stewart | Greg Swindell | Dave Stewart | Greg Swindell | | 185 | 119 | 66 |
| 1988-05-09 | vs DET | 31 | W 3-1 | 24-7 | 1 | 35,300 | Bob Welch | Jack Morris | Bob Welch | Jack Morris | Dennis Eckersley | 188 | 120 | 68 |
| 1988-05-10 | vs DET | 32 | L 2-8 | 24-8 | 1 | 23,341 | Curt Young | Walt Terrell | Walt Terrell | Curt Young | | 190 | 128 | 62 |
| 1988-05-11 | vs DET | 33 | L 4-8 | 24-9 | 1 | 26,860 | Storm Davis | Jeff Robinson | Guillermo Hernandez | Dennis Eckersley | | 194 | 136 | 58 |
| 1988-05-13 | @ BAL | 34 | L 1-4 | 24-10 | 1 | 20,336 | Dave Stewart | Jay Tibbs | Jay Tibbs | Dave Stewart | Tom Niedenfuer | 195 | 140 | 55 |
| 1988-05-14 | @ BAL | 35 | W 8-0 | 25-10 | 1 | 27,734 | Bob Welch | Mike Boddicker | Bob Welch | Mike Boddicker | | 203 | 140 | 63 |
| 1988-05-15 | @ BAL | 36 | W 7-4 | 26-10 | 1 | 29,664 | Curt Young | Mark Williamson | Curt Young | Mark Williamson | Dennis Eckersley | 210 | 144 | 66 |
| 1988-05-16 | @ BOS | 37 | W 3-0 | 27-10 | 1 | 24,642 | Storm Davis | Jeff Sellers | Storm Davis | Jeff Sellers | Dennis Eckersley | 213 | 144 | 69 |
| 1988-05-17 | @ BOS | 38 | W 12-7 | 28-10 | 1 | 28,407 | Steve Ontiveros | Steve Ellsworth | Steve Ontiveros | Steve Ellsworth | Rick Honeycutt | 225 | 151 | 74 |
| 1988-05-18 | @ BOS | 39 | L 1-4 | 28-11 | 1 | 24,683 | Dave Stewart | Oil Can Boyd | Oil Can Boyd | Dave Stewart | Lee Smith | 226 | 155 | 71 |
| 1988-05-20 | @ NYA | 40 | W 11-3 | 29-11 | 1 | 43,251 | Bob Welch | Tommy John | Bob Welch | Tommy John | | 237 | 158 | 79 |
| 1988-05-21 | @ NYA | 41 | L 2-3 | 29-12 | 1 | 40,266 | Curt Young | Rick Rhoden | Rick Rhoden | Curt Young | Dave Righetti | 239 | 161 | 78 |
| 1988-05-22 | @ NYA | 42 | L 0-2 | 29-13 | 1 | 54,719 | Storm Davis | John Candelaria | John Candelaria | Storm Davis | | 239 | 163 | 76 |
| 1988-05-23 | vs BAL | 43 | L 3-7 | 29-14 | 1 | 26,077 | Dave Stewart | Mike Boddicker | Mike Boddicker | Dave Stewart | Tom Niedenfuer | 242 | 170 | 72 |
| 1988-05-24 | vs BAL | 44 | W 6-0 | 30-14 | 1 | 15,375 | Steve Ontiveros | Jay Tibbs | Steve Ontiveros | Jay Tibbs | | 248 | 170 | 78 |
| 1988-05-25 | vs BAL | 45 | W 8-1 | 31-14 | 1 | 16,807 | Bob Welch | Mark Williamson | Bob Welch | Mark Williamson | | 256 | 171 | 85 |
| 1988-05-27 | vs BOS | 46 | W 3-2 | 32-14 | 1 | 32,723 | Curt Young | Bruce Hurst | Curt Young | Bruce Hurst | Dennis Eckersley | 259 | 173 | 86 |
| 1988-05-28 | vs BOS | 47 | W 7-5 | 33-14 | 1 | 43,177 | Dave Stewart | Oil Can Boyd | Rick Honeycutt | Dennis Lamp | Dennis Eckersley | 266 | 178 | 88 |
| 1988-05-29 | vs BOS | 48 | W 5-4 | 34-14 | 1 | 43,427 | Storm Davis | Jeff Sellers | Gene Nelson | Jeff Sellers | Eric Plunk | 271 | 182 | 89 |
| 1988-05-30 | vs NYA | 49 | W 3-2 | 35-14 | 1 | 44,218 | Bob Welch | Richard Dotson | Dennis Eckersley | Steve Shields | | 274 | 184 | 90 |
| 1988-05-31 | vs NYA | 50 | L 0-5 | 35-15 | 1 | 28,147 | Steve Ontiveros | Al Leiter | Neil Allen | Steve Ontiveros | | 274 | 189 | 85 |
| 1988-06-01 | vs NYA | 51 | W 4-3 | 36-15 | 1 | 38,771 | Curt Young | Charles Hudson | Gene Nelson | Charles Hudson | Dennis Eckersley | 278 | 192 | 86 |
| 1988-06-03 | @ MIN | 52 | W 8-5 | 37-15 | 1 | 43,177 | Dave Stewart | Les Straker | Dave Stewart | Les Straker | Dennis Eckersley | 286 | 197 | 89 |
| 1988-06-04 | @ MIN | 53 | W 6-4 | 38-15 | 1 | 52,008 | Storm Davis | Bert Blyleven | Storm Davis | Bert Blyleven | Dennis Eckersley | 292 | 201 | 91 |
| 1988-06-05 | @ MIN | 54 | L 3-4 | 38-16 | 1 | 43,567 | Bob Welch | Allan Anderson | Keith Atherton | Bob Welch | Jeff Reardon | 295 | 205 | 90 |
| 1988-06-06 | @ KCA | 55 | L 0-2 | 38-17 | 1 | 36,724 | Steve Ontiveros | Steve Farr | Steve Farr | Steve Ontiveros | Jerry Gleaton | 295 | 207 | 88 |
| 1988-06-07 | @ KCA | 56 | L 0-6 | 38-18 | 1 | 34,083 | Curt Young | Ted Power | Ted Power | Curt Young | | 295 | 213 | 82 |
| 1988-06-08 | @ KCA | 57 | L 4-5 | 38-19 | 1 | 32,002 | Dave Stewart | Bret Saberhagen | Bret Saberhagen | Dave Stewart | Jeff Montgomery | 299 | 218 | 81 |
| 1988-06-09 | @ TEX | 58 | L 2-5 | 38-20 | 1 | 31,435 | Storm Davis | Jeff Russell | Jeff Russell | Storm Davis | | 301 | 223 | 78 |
| 1988-06-10 | @ TEX | 59 | W 7-6 | 39-20 | 1 | 24,994 | Bob Welch | Paul Kilgus | Eric Plunk | Mitch Williams | Dennis Eckersley | 308 | 229 | 79 |
| 1988-06-11 | @ TEX | 60 | W 13-4 | 40-20 | 1 | 42,028 | Steve Ontiveros | Jose Guzman | Greg Cadaret | Jose Guzman | | 321 | 233 | 88 |
| 1988-06-12 | @ TEX | 61 | L 2-3 | 40-21 | 1 | 17,867 | Dave Stewart | Charlie Hough | Charlie Hough | Dave Stewart | | 323 | 236 | 87 |
| 1988-06-14 | vs KCA | 62 | L 1-2 | 40-22 | 1 | 21,380 | Storm Davis | Bret Saberhagen | Bret Saberhagen | Greg Cadaret | Gene Garber | 324 | 238 | 86 |
| 1988-06-15 | vs KCA | 63 | L 0-2 | 40-23 | 1 | 17,174 | Bob Welch | Charlie Leibrandt | Charlie Leibrandt | Bob Welch | | 324 | 240 | 84 |
| 1988-06-16 | vs KCA | 64 | L 5-9 | 40-24 | 1 | 23,579 | Curt Young | Mark Gubicza | Mark Gubicza | Curt Young | | 329 | 249 | 80 |
| 1988-06-17 | vs TEX | 65 | W 7-6 | 41-24 | 1 | 23,372 | Dave Stewart | Jose Guzman | Rick Honeycutt | Dale Mohorcic | | 336 | 255 | 81 |
| 1988-06-18 | vs TEX | 66 | W 2-1 | 42-24 | 1 | 34,449 | Todd Burns | Charlie Hough | Gene Nelson | Dale Mohorcic | | 338 | 256 | 82 |
| 1988-06-19 | vs TEX | 67 | L 4-5 | 42-25 | 1 | 35,133 | Storm Davis | Ray Hayward | Craig McMurtry | Rick Honeycutt | Mitch Williams | 342 | 261 | 81 |
| 1988-06-20 | @ MIL | 68 | W 5-4 | 43-25 | 1 | 25,180 | Bob Welch | Teddy Higuera | Eric Plunk | Chuck Crim | Dennis Eckersley | 347 | 265 | 82 |
| 1988-06-21 | @ MIL | 69 | W 4-2 | 44-25 | 1 | 26,222 | Curt Young | Chris Bosio | Curt Young | Chris Bosio | Dennis Eckersley | 351 | 267 | 84 |
| 1988-06-22 | @ MIL | 70 | W 6-2 | 45-25 | 1 | 30,772 | Dave Stewart | Don August | Dave Stewart | Don August | | 357 | 269 | 88 |
| 1988-06-24 | vs MIN | 71 | L 5-11 | 45-26 | 1 | 30,826 | Storm Davis | Bert Blyleven | Keith Atherton | Gene Nelson | | 362 | 280 | 82 |
| 1988-06-25 | vs MIN | 72 | W 4-3 | 46-26 | 1 | 38,299 | Bob Welch | Allan Anderson | Bob Welch | Allan Anderson | Dennis Eckersley | 366 | 283 | 83 |
| 1988-06-26 | vs MIN | 73 | L 0-11 | 46-28 | 1 | 0 | Curt Young | Charlie Lea | Charlie Lea | Curt Young | Juan Berenguer | 366 | 294 | 72 |
| 1988-06-26 | vs MIN | 74 | L 0-5 | 46-28 | 1 | 43,154 | Dave Stewart | Frank Viola | Frank Viola | Dave Stewart | Keith Atherton | 366 | 299 | 67 |
| 1988-06-27 | vs MIL | 75 | W 5-4 | 47-28 | 1 | 25,933 | Todd Burns | Chris Bosio | Dennis Eckersley | Dan Plesac | | 371 | 303 | 68 |
| 1988-06-28 | vs MIL | 76 | L 1-4 | 47-29 | 1 | 23,333 | Storm Davis | Don August | Don August | Storm Davis | | 372 | 307 | 65 |
| 1988-06-29 | vs MIL | 77 | W 7-2 | 48-29 | 1 | 23,506 | Bob Welch | Bill Wegman | Bob Welch | Bill Wegman | | 379 | 309 | 70 |
| 1988-07-01 | @ TOR | 78 | W 2-1 | 49-29 | 1 | 35,243 | Dave Stewart | Dave Stieb | Dave Stewart | Dave Stieb | Dennis Eckersley | 381 | 310 | 71 |
| 1988-07-02 | @ TOR | 79 | W 11-3 | 50-29 | 1 | 33,511 | Curt Young | Mike Flanagan | Curt Young | Mike Flanagan | Gene Nelson | 392 | 313 | 79 |
| 1988-07-03 | @ TOR | 80 | W 9-8 | 51-29 | 1 | 32,329 | Storm Davis | Todd Stottlemyre | Todd Burns | John Cerutti | | 401 | 321 | 80 |
| 1988-07-04 | @ CLE | 81 | W 4-2 | 52-29 | 1 | 20,891 | Bob Welch | Tom Candiotti | Greg Cadaret | Brad Havens | Dennis Eckersley | 405 | 323 | 82 |
| 1988-07-05 | @ CLE | 82 | L 0-3 | 52-31 | 1 | 0 | Dave Stewart | Scott Bailes | Scott Bailes | Dave Stewart | | 405 | 326 | 79 |
| 1988-07-05 | @ CLE | 83 | L 2-4 | 52-31 | 1 | 17,983 | Rich Bordi | Rick Rodriguez | Rick Rodriguez | Rich Bordi | Doug Jones | 407 | 330 | 77 |
| 1988-07-06 | @ CLE | 84 | L 6-8 | 52-32 | 1 | 16,317 | Todd Burns | Greg Swindell | Don Gordon | Rick Honeycutt | | 413 | 338 | 75 |
| 1988-07-07 | @ DET | 85 | L 1-8 | 52-33 | 1 | 28,061 | Curt Young | Jeff Robinson | Jeff Robinson | Curt Young | | 414 | 346 | 68 |
| 1988-07-08 | @ DET | 86 | W 3-2 | 53-33 | 1 | 37,498 | Storm Davis | Eric King | Storm Davis | Eric King | Dennis Eckersley | 417 | 348 | 69 |
| 1988-07-09 | @ DET | 87 | L 3-4 | 53-34 | 1 | 43,016 | Bob Welch | Frank Tanana | Frank Tanana | Bob Welch | Guillermo Hernandez | 420 | 352 | 68 |
| 1988-07-10 | @ DET | 88 | W 8-2 | 54-34 | 1 | 36,519 | Dave Stewart | Walt Terrell | Dave Stewart | Walt Terrell | | 428 | 354 | 74 |
| 1988-07-14 | vs TOR | 89 | L 1-7 | 54-35 | 1 | 20,639 | Bob Welch | Mike Flanagan | Mike Flanagan | Bob Welch | | 429 | 361 | 68 |
| 1988-07-15 | vs TOR | 90 | L 0-1 | 54-36 | 1 | 26,476 | Dave Stewart | Jimmy Key | Jimmy Key | Dave Stewart | | 429 | 362 | 67 |
| 1988-07-16 | vs TOR | 91 | W 4-1 | 55-36 | 1 | 33,287 | Storm Davis | Dave Stieb | Storm Davis | Dave Stieb | Dennis Eckersley | 433 | 363 | 70 |
| 1988-07-17 | vs TOR | 92 | L 6-9 | 55-37 | 1 | 31,695 | Curt Young | Todd Stottlemyre | Duane Ward | Curt Young | Tom Henke | 439 | 372 | 67 |
| 1988-07-18 | vs CLE | 93 | W 7-2 | 56-37 | 1 | 27,849 | Todd Burns | Scott Bailes | Todd Burns | Scott Bailes | | 446 | 374 | 72 |
| 1988-07-19 | vs CLE | 94 | W 4-2 | 58-37 | 1 | 0 | Bob Welch | Greg Swindell | Bob Welch | Greg Swindell | Dennis Eckersley | 450 | 376 | 74 |
| 1988-07-19 | vs CLE | 95 | W 9-6 | 58-37 | 1 | 17,299 | Rich Bordi | Rick Rodriguez | Greg Cadaret | Don Gordon | Dennis Eckersley | 459 | 382 | 77 |
| 1988-07-20 | vs CLE | 96 | L 4-5 | 58-38 | 1 | 27,439 | Dave Stewart | John Farrell | John Farrell | Dave Stewart | Doug Jones | 463 | 387 | 76 |
| 1988-07-22 | vs DET | 97 | W 4-1 | 59-38 | 1 | 35,480 | Storm Davis | Jeff Robinson | Storm Davis | Jeff Robinson | Dennis Eckersley | 467 | 388 | 79 |
| 1988-07-23 | vs DET | 98 | W 4-1 | 60-38 | 1 | 43,185 | Todd Burns | Frank Tanana | Todd Burns | Frank Tanana | Eric Plunk | 471 | 389 | 82 |
| 1988-07-24 | vs DET | 99 | W 1-0 | 61-38 | 1 | 43,146 | Bob Welch | Walt Terrell | Bob Welch | Walt Terrell | | 472 | 389 | 83 |
| 1988-07-25 | @ CAL | 100 | L 1-2 | 61-39 | 1 | 30,928 | Dave Stewart | Kirk McCaskill | Kirk McCaskill | Dave Stewart | | 473 | 391 | 82 |
| 1988-07-26 | @ CAL | 101 | W 6-2 | 62-39 | 1 | 35,838 | Storm Davis | Mike Witt | Storm Davis | Mike Witt | | 479 | 393 | 86 |
| 1988-07-27 | @ CAL | 102 | L 8-9 | 62-40 | 1 | 33,714 | Todd Burns | Terry Clark | Donnie Moore | Jim Corsi | | 487 | 402 | 85 |
| 1988-07-29 | @ SEA | 103 | L 3-5 | 62-41 | 1 | 14,685 | Bob Welch | Mark Langston | Michael Jackson | Dennis Eckersley | | 490 | 407 | 83 |
| 1988-07-30 | @ SEA | 104 | W 5-2 | 63-41 | 1 | 19,787 | Dave Stewart | Mike Moore | Dave Stewart | Mike Moore | | 495 | 409 | 86 |
| 1988-07-31 | @ SEA | 105 | W 6-2 | 64-41 | 1 | 12,930 | Storm Davis | Scott Bankhead | Storm Davis | Scott Bankhead | Greg Cadaret | 501 | 411 | 90 |
| 1988-08-01 | @ CHA | 106 | W 10-2 | 65-41 | 1 | 18,712 | Todd Burns | Melido Perez | Todd Burns | Melido Perez | | 511 | 413 | 98 |
| 1988-08-02 | @ CHA | 107 | L 5-7 | 65-42 | 1 | 13,383 | Steve Ontiveros | Dave LaPoint | Dave LaPoint | Steve Ontiveros | Bobby Thigpen | 516 | 420 | 96 |
| 1988-08-03 | @ CHA | 108 | W 4-3 | 66-42 | 1 | 19,515 | Bob Welch | Bill Long | Gene Nelson | Bobby Thigpen | Dennis Eckersley | 520 | 423 | 97 |
| 1988-08-04 | vs SEA | 109 | W 2-0 | 67-42 | 1 | 18,313 | Dave Stewart | Mike Moore | Dave Stewart | Mike Moore | | 522 | 423 | 99 |
| 1988-08-05 | vs SEA | 110 | W 4-1 | 68-42 | 1 | 19,318 | Storm Davis | Scott Bankhead | Storm Davis | Scott Bankhead | Dennis Eckersley | 526 | 424 | 102 |
| 1988-08-06 | vs SEA | 111 | W 5-4 | 69-42 | 1 | 30,574 | Todd Burns | Bill Swift | Gene Nelson | Michael Jackson | | 531 | 428 | 103 |
| 1988-08-07 | vs SEA | 112 | L 7-12 | 69-43 | 1 | 24,351 | Jim Corsi | Dennis Powell | Mike Schooler | Eric Plunk | | 538 | 440 | 98 |
| 1988-08-08 | vs CHA | 113 | W 9-5 | 70-43 | 1 | 25,111 | Bob Welch | Bill Long | Bob Welch | Bill Long | Dennis Eckersley | 547 | 445 | 102 |
| 1988-08-09 | vs CHA | 114 | W 8-1 | 71-43 | 1 | 15,811 | Dave Stewart | Jeff Bittiger | Dave Stewart | Jeff Bittiger | | 555 | 446 | 109 |
| 1988-08-10 | vs CHA | 115 | W 2-1 | 72-43 | 1 | 26,694 | Curt Young | Jack McDowell | Greg Cadaret | Ricky Horton | | 557 | 447 | 110 |
| 1988-08-11 | vs CAL | 116 | W 7-2 | 73-43 | 1 | 20,195 | Storm Davis | Terry Clark | Dennis Eckersley | Terry Clark | | 564 | 449 | 115 |
| 1988-08-12 | vs CAL | 117 | W 4-0 | 74-43 | 1 | 34,518 | Todd Burns | Chuck Finley | Todd Burns | Chuck Finley | Greg Cadaret | 568 | 449 | 119 |
| 1988-08-13 | vs CAL | 118 | W 6-2 | 75-43 | 1 | 33,314 | Bob Welch | Stew Cliburn | Bob Welch | Stew Cliburn | Rick Honeycutt | 574 | 451 | 123 |
| 1988-08-14 | vs CAL | 119 | L 4-6 | 75-44 | 1 | 40,013 | Dave Stewart | Mike Witt | Mike Witt | Gene Nelson | Bryan Harvey | 578 | 457 | 121 |
| 1988-08-16 | @ BAL | 120 | W 6-3 | 76-44 | 1 | 22,239 | Storm Davis | Jay Tibbs | Storm Davis | Jay Tibbs | Dennis Eckersley | 584 | 460 | 124 |
| 1988-08-17 | @ BAL | 121 | W 10-4 | 77-44 | 1 | 18,127 | Curt Young | Gordon Dillard | Curt Young | Doug Sisk | Eric Plunk | 594 | 464 | 130 |
| 1988-08-18 | @ BAL | 122 | L 1-10 | 77-45 | 1 | 27,723 | Bob Welch | Jeff Ballard | Jeff Ballard | Bob Welch | | 595 | 474 | 121 |
| 1988-08-19 | @ BOS | 123 | L 6-7 | 77-46 | 1 | 33,993 | Dave Stewart | Mike Smithson | Bob Stanley | Dave Stewart | | 601 | 481 | 120 |
| 1988-08-20 | @ BOS | 124 | L 5-7 | 77-47 | 1 | 34,372 | Todd Burns | Oil Can Boyd | Jeff Sellers | Todd Burns | Lee Smith | 606 | 488 | 118 |
| 1988-08-21 | @ BOS | 125 | W 5-4 | 78-47 | 1 | 33,282 | Storm Davis | Wes Gardner | Rick Honeycutt | Bob Stanley | Dennis Eckersley | 611 | 492 | 119 |
| 1988-08-22 | @ NYA | 126 | W 9-2 | 79-47 | 1 | 34,583 | Curt Young | Charles Hudson | Curt Young | Charles Hudson | | 620 | 494 | 126 |
| 1988-08-23 | @ NYA | 127 | L 4-5 | 79-48 | 1 | 32,250 | Bob Welch | Tommy John | Dave Righetti | Greg Cadaret | | 624 | 499 | 125 |
| 1988-08-24 | @ NYA | 128 | L 6-7 | 79-49 | 1 | 34,520 | Dave Stewart | John Candelaria | Cecilio Guante | Gene Nelson | | 630 | 506 | 124 |
| 1988-08-26 | vs BAL | 129 | W 8-5 | 80-49 | 1 | 22,136 | Storm Davis | Jay Tibbs | Storm Davis | Jay Tibbs | Eric Plunk | 638 | 511 | 127 |
| 1988-08-27 | vs BAL | 130 | W 5-1 | 81-49 | 1 | 33,660 | Todd Burns | Oswaldo Peraza | Todd Burns | Oswaldo Peraza | Greg Cadaret | 643 | 512 | 131 |
| 1988-08-28 | vs BAL | 131 | L 1-2 | 81-50 | 1 | 21,090 | Curt Young | Jose Bautista | Mark Williamson | Gene Nelson | Tom Niedenfuer | 644 | 514 | 130 |
| 1988-08-29 | vs BOS | 132 | W 3-1 | 82-50 | 1 | 40,423 | Bob Welch | Mike Boddicker | Bob Welch | Mike Boddicker | Dennis Eckersley | 647 | 515 | 132 |
| 1988-08-30 | vs BOS | 133 | W 1-0 | 83-50 | 1 | 35,220 | Dave Stewart | Roger Clemens | Dave Stewart | Roger Clemens | | 648 | 515 | 133 |
| 1988-08-31 | vs BOS | 134 | W 7-2 | 84-50 | 1 | 37,151 | Storm Davis | Mike Smithson | Storm Davis | Mike Smithson | | 655 | 517 | 138 |
| 1988-09-02 | vs NYA | 135 | L 1-4 | 84-51 | 1 | 36,465 | Curt Young | Tommy John | Tommy John | Curt Young | Dave Righetti | 656 | 521 | 135 |
| 1988-09-03 | vs NYA | 136 | W 5-4 | 85-51 | 1 | 43,074 | Bob Welch | Ron Guidry | Eric Plunk | Dale Mohorcic | Dennis Eckersley | 661 | 525 | 136 |
| 1988-09-04 | vs NYA | 137 | W 11-2 | 86-51 | 1 | 43,042 | Dave Stewart | Richard Dotson | Dave Stewart | Richard Dotson | | 672 | 527 | 145 |
| 1988-09-05 | @ TEX | 138 | W 11-4 | 87-51 | 1 | 10,934 | Storm Davis | Paul Kilgus | Storm Davis | Paul Kilgus | | 683 | 531 | 152 |
| 1988-09-06 | @ TEX | 139 | L 1-3 | 87-52 | 1 | 9,040 | Todd Burns | Charlie Hough | Charlie Hough | Todd Burns | Cecilio Guante | 684 | 534 | 150 |
| 1988-09-07 | @ TEX | 140 | W 6-3 | 88-52 | 1 | 11,409 | Dave Otto | Jose Guzman | Gene Nelson | Jose Guzman | Dennis Eckersley | 690 | 537 | 153 |
| 1988-09-08 | @ KCA | 141 | W 5-1 | 89-52 | 1 | 29,167 | Curt Young | Bret Saberhagen | Curt Young | Bret Saberhagen | Dennis Eckersley | 695 | 538 | 157 |
| 1988-09-09 | @ KCA | 142 | W 14-6 | 90-52 | 1 | 26,675 | Dave Stewart | Jose De Jesus | Dave Stewart | Jose De Jesus | Rick Honeycutt | 709 | 544 | 165 |
| 1988-09-10 | @ KCA | 143 | L 4-9 | 90-53 | 1 | 37,983 | Storm Davis | Charlie Leibrandt | Charlie Leibrandt | Storm Davis | | 713 | 553 | 160 |
| 1988-09-11 | @ KCA | 144 | W 8-7 | 91-53 | 1 | 28,953 | Bob Welch | Mark Gubicza | Dennis Eckersley | Steve Farr | | 721 | 560 | 161 |
| 1988-09-13 | vs TEX | 145 | W 2-1 | 92-53 | 1 | 16,255 | Curt Young | Jose Guzman | Curt Young | Jose Guzman | Dennis Eckersley | 723 | 561 | 162 |
| 1988-09-14 | vs TEX | 146 | L 1-9 | 92-54 | 1 | 14,519 | Dave Stewart | Kevin Brown | Kevin Brown | Dave Stewart | | 724 | 570 | 154 |
| 1988-09-15 | vs TEX | 147 | W 6-2 | 93-54 | 1 | 17,265 | Todd Burns | Bobby Witt | Todd Burns | Bobby Witt | | 730 | 572 | 158 |
| 1988-09-16 | vs KCA | 148 | L 0-3 | 93-55 | 1 | 33,881 | Bob Welch | Mark Gubicza | Mark Gubicza | Bob Welch | | 730 | 575 | 155 |
| 1988-09-17 | vs KCA | 149 | W 3-2 | 94-55 | 1 | 43,875 | Dave Otto | Tom Gordon | Eric Plunk | Tom Gordon | Dennis Eckersley | 733 | 577 | 156 |
| 1988-09-18 | vs KCA | 150 | W 3-2 | 95-55 | 1 | 35,515 | Curt Young | Bret Saberhagen | Greg Cadaret | Steve Farr | | 736 | 579 | 157 |
| 1988-09-19 | vs MIN | 151 | W 5-3 | 96-55 | 1 | 42,186 | Dave Stewart | Freddie Toliver | Dave Stewart | Freddie Toliver | Dennis Eckersley | 741 | 582 | 159 |
| 1988-09-20 | vs MIN | 152 | W 12-3 | 97-55 | 1 | 29,585 | Storm Davis | Frank Viola | Storm Davis | Frank Viola | Rick Honeycutt | 753 | 585 | 168 |
| 1988-09-21 | vs MIN | 153 | W 6-3 | 98-55 | 1 | 23,200 | Bob Welch | Bert Blyleven | Bob Welch | Bert Blyleven | Dennis Eckersley | 759 | 588 | 171 |
| 1988-09-23 | @ MIL | 154 | W 9-8 | 99-55 | 1 | 24,163 | Curt Young | Juan Nieves | Gene Nelson | Chris Bosio | Todd Burns | 768 | 596 | 172 |
| 1988-09-24 | @ MIL | 155 | W 5-2 | 100-55 | 1 | 32,021 | Dave Stewart | Bill Wegman | Dave Stewart | Bill Wegman | Dennis Eckersley | 773 | 598 | 175 |
| 1988-09-25 | @ MIL | 156 | L 2-4 | 100-56 | 1 | 21,472 | Storm Davis | Teddy Higuera | Teddy Higuera | Storm Davis | Chris Bosio | 775 | 602 | 173 |
| 1988-09-27 | @ MIN | 157 | L 0-5 | 100-57 | 1 | 48,300 | Bob Welch | Allan Anderson | Allan Anderson | Bob Welch | | 775 | 607 | 168 |
| 1988-09-28 | @ MIN | 158 | W 5-2 | 101-57 | 1 | 47,620 | Todd Burns | Bert Blyleven | Todd Burns | Bert Blyleven | Dennis Eckersley | 780 | 609 | 171 |
| 1988-09-29 | @ MIN | 159 | W 6-2 | 102-57 | 1 | 39,528 | Curt Young | Freddie Toliver | Curt Young | Freddie Toliver | | 786 | 611 | 175 |
| 1988-09-30 | vs MIL | 160 | W 7-1 | 103-57 | 1 | 30,395 | Dave Stewart | Bill Wegman | Dave Stewart | Bill Wegman | | 793 | 612 | 181 |
| 1988-10-01 | vs MIL | 161 | L 3-8 | 103-58 | 1 | 30,798 | Storm Davis | Teddy Higuera | Teddy Higuera | Storm Davis | Chris Bosio | 796 | 620 | 176 |
| 1988-10-02 | vs MIL | 162 | W 4-0 | 104-58 | 1 | 43,148 | Bob Welch | Don August | Bob Welch | Don August | | 800 | 620 | 180 |