| 1988-04-05 | vs MIN | 1 | W 8-0 | 1-0 | 3 | 55,802 | Rick Rhoden | Frank Viola | Rick Rhoden | Frank Viola | | 8 | 0 | 8 |
| 1988-04-06 | vs MIN | 2 | W 5-3 | 2-0 | 2 | 32,756 | John Candelaria | Les Straker | Cecilio Guante | Juan Berenguer | Dave Righetti | 13 | 3 | 10 |
| 1988-04-08 | vs MIL | 3 | W 6-4 | 3-0 | 1 | 20,927 | Richard Dotson | Juan Nieves | Richard Dotson | Juan Nieves | Dave Righetti | 19 | 7 | 12 |
| 1988-04-09 | vs MIL | 4 | W 4-1 | 4-0 | 1 | 27,021 | Al Leiter | Bill Wegman | Al Leiter | Bill Wegman | Dave Righetti | 23 | 8 | 15 |
| 1988-04-10 | vs MIL | 5 | W 7-6 | 5-0 | 1 | 36,214 | Tommy John | Teddy Higuera | Tim Stoddard | Chuck Crim | Cecilio Guante | 30 | 14 | 16 |
| 1988-04-11 | @ TOR | 6 | L 9-17 | 5-1 | 2 | 45,185 | Rick Rhoden | Mike Flanagan | David Wells | Rick Rhoden | | 39 | 31 | 8 |
| 1988-04-12 | @ TOR | 7 | W 12-3 | 6-1 | 1 | 24,116 | John Candelaria | Jim Clancy | John Candelaria | Jim Clancy | | 51 | 34 | 17 |
| 1988-04-13 | @ TOR | 8 | W 5-1 | 7-1 | 1 | 24,105 | Richard Dotson | Dave Stieb | Richard Dotson | Dave Stieb | | 56 | 35 | 21 |
| 1988-04-14 | @ TOR | 9 | W 7-3 | 8-1 | 1 | 24,524 | Al Leiter | Jimmy Key | Al Leiter | Jimmy Key | | 63 | 38 | 25 |
| 1988-04-15 | @ MIL | 10 | W 7-1 | 9-1 | 1 | 55,887 | Tommy John | Mike Birkbeck | Tommy John | Mike Birkbeck | | 70 | 39 | 31 |
| 1988-04-16 | @ MIL | 11 | L 2-9 | 9-2 | 2 | 24,972 | Rick Rhoden | Chris Bosio | Chris Bosio | Rick Rhoden | | 72 | 48 | 24 |
| 1988-04-17 | @ MIL | 12 | L 3-6 | 9-3 | 2 | 22,199 | John Candelaria | Teddy Higuera | Teddy Higuera | John Candelaria | Dan Plesac | 75 | 54 | 21 |
| 1988-04-18 | @ MIN | 13 | W 18-5 | 10-3 | 2 | 30,442 | Richard Dotson | Bert Blyleven | Charles Hudson | Bert Blyleven | | 93 | 59 | 34 |
| 1988-04-19 | @ MIN | 14 | W 7-6 | 11-3 | 2 | 23,724 | Al Leiter | Joe Niekro | Al Leiter | Joe Niekro | Dave Righetti | 100 | 65 | 35 |
| 1988-04-20 | @ MIN | 15 | W 7-6 | 12-3 | 2 | 22,369 | Tommy John | Frank Viola | Dave Righetti | Jeff Reardon | | 107 | 71 | 36 |
| 1988-04-22 | vs TOR | 16 | L 4-6 | 12-4 | 2 | 33,314 | Rick Rhoden | Mike Flanagan | David Wells | Tim Stoddard | Tom Henke | 111 | 77 | 34 |
| 1988-04-23 | vs TOR | 17 | L 2-3 | 12-5 | 2 | 24,046 | John Candelaria | John Cerutti | John Cerutti | John Candelaria | Tom Henke | 113 | 80 | 33 |
| 1988-04-24 | vs TOR | 18 | W 5-3 | 13-5 | 2 | 52,073 | Richard Dotson | Jim Clancy | Charles Hudson | Mark Eichhorn | | 118 | 83 | 35 |
| 1988-04-26 | vs KCA | 19 | W 5-4 | 14-5 | 2 | 20,364 | Al Leiter | Charlie Leibrandt | Cecilio Guante | Charlie Leibrandt | Charles Hudson | 123 | 87 | 36 |
| 1988-04-27 | vs KCA | 20 | L 1-3 | 14-6 | 3 | 20,484 | Tommy John | Mark Gubicza | Buddy Black | Charles Hudson | Gene Garber | 124 | 90 | 34 |
| 1988-04-28 | vs KCA | 21 | L 3-6 | 14-7 | 3 | 17,102 | Rick Rhoden | Floyd Bannister | Floyd Bannister | Rick Rhoden | Dan Quisenberry | 127 | 96 | 31 |
| 1988-04-29 | vs TEX | 22 | W 2-1 | 15-7 | 3 | 20,277 | John Candelaria | Charlie Hough | John Candelaria | Charlie Hough | | 129 | 97 | 32 |
| 1988-04-30 | vs TEX | 23 | W 15-3 | 16-7 | 3 | 21,011 | Richard Dotson | Bobby Witt | Richard Dotson | Bobby Witt | | 144 | 100 | 44 |
| 1988-05-01 | vs TEX | 24 | L 1-5 | 16-8 | 3 | 40,268 | Al Leiter | Paul Kilgus | Paul Kilgus | Al Leiter | Dale Mohorcic | 145 | 105 | 40 |
| 1988-05-02 | @ CHA | 25 | W 6-4 | 17-8 | 2 | 14,786 | Tommy John | Jerry Reuss | Tim Stoddard | Bobby Thigpen | John Candelaria | 151 | 109 | 42 |
| 1988-05-03 | @ CHA | 26 | W 4-1 | 18-8 | 1 | 13,293 | Charles Hudson | Dave LaPoint | Charles Hudson | Dave LaPoint | Cecilio Guante | 155 | 110 | 45 |
| 1988-05-04 | @ KCA | 27 | W 4-3 | 19-8 | 1 | 27,422 | John Candelaria | Charlie Leibrandt | John Candelaria | Ted Power | Tim Stoddard | 159 | 113 | 46 |
| 1988-05-05 | @ KCA | 28 | W 5-3 | 20-8 | 1 | 36,255 | Richard Dotson | Mark Gubicza | Richard Dotson | Mark Gubicza | Cecilio Guante | 164 | 116 | 48 |
| 1988-05-06 | @ TEX | 29 | L 6-7 | 20-9 | 1 | 25,602 | Al Leiter | Paul Kilgus | Paul Kilgus | Al Leiter | Jose Cecena | 170 | 123 | 47 |
| 1988-05-07 | @ TEX | 30 | L 2-3 | 20-10 | 1 | 33,611 | Tommy John | Jose Guzman | Dale Mohorcic | Cecilio Guante | | 172 | 126 | 46 |
| 1988-05-08 | @ TEX | 31 | L 8-10 | 20-11 | 1 | 21,761 | Charles Hudson | Ray Hayward | Jeff Russell | Steve Shields | Dale Mohorcic | 180 | 136 | 44 |
| 1988-05-10 | vs CHA | 32 | W 17-3 | 21-11 | 1 | 18,118 | John Candelaria | Ricky Horton | John Candelaria | Ricky Horton | | 197 | 139 | 58 |
| 1988-05-11 | vs CHA | 33 | W 12-2 | 22-11 | 1 | 21,001 | Richard Dotson | Jack McDowell | Richard Dotson | Jack McDowell | | 209 | 141 | 68 |
| 1988-05-13 | vs CAL | 34 | L 4-5 | 22-12 | 1 | 30,113 | Al Leiter | Kirk McCaskill | Willie Fraser | Cecilio Guante | DeWayne Buice | 213 | 146 | 67 |
| 1988-05-14 | vs CAL | 35 | W 6-2 | 23-12 | 1 | 33,119 | Tommy John | Dan Petry | Tommy John | Dan Petry | Dave Righetti | 219 | 148 | 71 |
| 1988-05-15 | vs CAL | 36 | W 9-2 | 24-12 | 1 | 51,006 | Charles Hudson | Chuck Finley | Charles Hudson | Chuck Finley | | 228 | 150 | 78 |
| 1988-05-16 | vs SEA | 37 | W 3-1 | 25-12 | 1 | 17,651 | John Candelaria | Mike Moore | John Candelaria | Mike Moore | Dave Righetti | 231 | 151 | 80 |
| 1988-05-17 | vs SEA | 38 | L 2-6 | 25-13 | 1 | 17,858 | Richard Dotson | Bill Swift | Bill Swift | Richard Dotson | | 233 | 157 | 76 |
| 1988-05-20 | vs OAK | 39 | L 3-11 | 25-14 | 1 | 43,251 | Tommy John | Bob Welch | Bob Welch | Tommy John | | 236 | 168 | 68 |
| 1988-05-21 | vs OAK | 40 | W 3-2 | 26-14 | 1 | 40,266 | Rick Rhoden | Curt Young | Rick Rhoden | Curt Young | Dave Righetti | 239 | 170 | 69 |
| 1988-05-22 | vs OAK | 41 | W 2-0 | 27-14 | 1 | 54,719 | John Candelaria | Storm Davis | John Candelaria | Storm Davis | | 241 | 170 | 71 |
| 1988-05-23 | @ CAL | 42 | W 5-2 | 28-14 | 1 | 30,521 | Richard Dotson | Mike Witt | Cecilio Guante | Mike Witt | Dave Righetti | 246 | 172 | 74 |
| 1988-05-24 | @ CAL | 43 | W 5-3 | 29-14 | 1 | 32,805 | Al Leiter | Kirk McCaskill | Al Leiter | Kirk McCaskill | Dave Righetti | 251 | 175 | 76 |
| 1988-05-25 | @ CAL | 44 | W 4-2 | 30-14 | 1 | 48,198 | Charles Hudson | Dan Petry | Neil Allen | DeWayne Buice | | 255 | 177 | 78 |
| 1988-05-27 | @ SEA | 45 | W 5-1 | 31-14 | 1 | 19,933 | Tommy John | Scott Bankhead | Tommy John | Scott Bankhead | Cecilio Guante | 260 | 178 | 82 |
| 1988-05-28 | @ SEA | 46 | L 1-6 | 31-15 | 1 | 33,449 | Rick Rhoden | Bill Swift | Bill Swift | Rick Rhoden | | 261 | 184 | 77 |
| 1988-05-29 | @ SEA | 47 | W 7-3 | 32-15 | 1 | 26,931 | John Candelaria | Mike Campbell | John Candelaria | Mike Campbell | Cecilio Guante | 268 | 187 | 81 |
| 1988-05-30 | @ OAK | 48 | L 2-3 | 32-16 | 1 | 44,218 | Richard Dotson | Bob Welch | Dennis Eckersley | Steve Shields | | 270 | 190 | 80 |
| 1988-05-31 | @ OAK | 49 | W 5-0 | 33-16 | 1 | 28,147 | Al Leiter | Steve Ontiveros | Neil Allen | Steve Ontiveros | | 275 | 190 | 85 |
| 1988-06-01 | @ OAK | 50 | L 3-4 | 33-17 | 1 | 38,771 | Charles Hudson | Curt Young | Gene Nelson | Charles Hudson | Dennis Eckersley | 278 | 194 | 84 |
| 1988-06-03 | @ BAL | 51 | W 4-0 | 34-17 | 1 | 33,802 | Tommy John | Jose Bautista | Tommy John | Jose Bautista | | 282 | 194 | 88 |
| 1988-06-04 | @ BAL | 52 | L 6-7 | 34-18 | 1 | 36,499 | Rick Rhoden | Mike Boddicker | Doug Sisk | Hipolito Pena | | 288 | 201 | 87 |
| 1988-06-05 | @ BAL | 53 | W 9-2 | 35-18 | 1 | 36,665 | Richard Dotson | Jay Tibbs | Richard Dotson | Jay Tibbs | | 297 | 203 | 94 |
| 1988-06-06 | vs BOS | 54 | L 2-3 | 35-19 | 1 | 37,244 | Neil Allen | Bruce Hurst | Bruce Hurst | Neil Allen | Lee Smith | 299 | 206 | 93 |
| 1988-06-07 | vs BOS | 55 | W 4-3 | 36-19 | 1 | 37,081 | Charles Hudson | Oil Can Boyd | Charles Hudson | Oil Can Boyd | Cecilio Guante | 303 | 209 | 94 |
| 1988-06-08 | vs BOS | 56 | L 3-4 | 36-20 | 1 | 42,804 | Tommy John | Roger Clemens | Roger Clemens | Tommy John | Lee Smith | 306 | 213 | 93 |
| 1988-06-10 | vs BAL | 57 | L 3-5 | 36-21 | 1 | 33,410 | Rick Rhoden | Mike Boddicker | Mike Boddicker | Rick Rhoden | | 309 | 218 | 91 |
| 1988-06-11 | vs BAL | 58 | W 8-6 | 37-21 | 1 | 33,826 | John Candelaria | Jeff Ballard | John Candelaria | Jeff Ballard | Dave Righetti | 317 | 224 | 93 |
| 1988-06-12 | vs BAL | 59 | W 6-5 | 38-21 | 1 | 51,142 | Tommy John | Jay Tibbs | Cecilio Guante | Tom Niedenfuer | | 323 | 229 | 94 |
| 1988-06-13 | @ BOS | 60 | W 12-6 | 39-21 | 1 | 34,288 | Richard Dotson | Roger Clemens | Richard Dotson | Roger Clemens | Cecilio Guante | 335 | 235 | 100 |
| 1988-06-14 | @ BOS | 61 | L 3-7 | 39-22 | 1 | 33,367 | Neil Allen | Mike Smithson | Mike Smithson | Neil Allen | Lee Smith | 338 | 242 | 96 |
| 1988-06-15 | @ BOS | 62 | L 3-8 | 39-23 | 1 | 33,870 | Al Leiter | Bruce Hurst | Bruce Hurst | Al Leiter | | 341 | 250 | 91 |
| 1988-06-17 | @ CLE | 63 | L 4-6 | 39-24 | 1 | 56,485 | John Candelaria | John Farrell | John Farrell | John Candelaria | Doug Jones | 345 | 256 | 89 |
| 1988-06-18 | @ CLE | 64 | W 6-3 | 40-24 | 1 | 48,936 | Rick Rhoden | Scott Bailes | Rick Rhoden | Scott Bailes | Cecilio Guante | 351 | 259 | 92 |
| 1988-06-19 | @ CLE | 65 | L 3-11 | 40-25 | 1 | 49,912 | Richard Dotson | Tom Candiotti | Tom Candiotti | Richard Dotson | | 354 | 270 | 84 |
| 1988-06-20 | @ DET | 66 | L 1-2 | 40-26 | 2 | 33,660 | Tommy John | Jeff Robinson | Guillermo Hernandez | Cecilio Guante | | 355 | 272 | 83 |
| 1988-06-21 | @ DET | 67 | L 6-7 | 40-27 | 2 | 26,535 | Al Leiter | Jack Morris | Eric King | Cecilio Guante | | 361 | 279 | 82 |
| 1988-06-22 | @ DET | 68 | L 2-3 | 40-28 | 2 | 33,014 | John Candelaria | Frank Tanana | Mike Henneman | Charles Hudson | | 363 | 282 | 81 |
| 1988-06-23 | vs CLE | 69 | W 4-3 | 41-28 | 2 | 31,341 | Rick Rhoden | Scott Bailes | Dave Righetti | Jon Perlman | | 367 | 285 | 82 |
| 1988-06-24 | vs CLE | 70 | L 5-7 | 41-29 | 2 | 38,049 | Richard Dotson | Tom Candiotti | Brad Havens | Richard Dotson | Doug Jones | 372 | 292 | 80 |
| 1988-06-25 | vs CLE | 71 | W 4-1 | 42-29 | 2 | 38,202 | Tommy John | Greg Swindell | Tommy John | Greg Swindell | Cecilio Guante | 376 | 293 | 83 |
| 1988-06-26 | vs CLE | 72 | W 4-3 | 43-29 | 2 | 53,037 | Charles Hudson | Rick Rodriguez | Dave Righetti | Buddy Black | | 380 | 296 | 84 |
| 1988-06-27 | vs DET | 73 | L 3-6 | 43-30 | 2 | 26,862 | John Candelaria | Jack Morris | Jack Morris | John Candelaria | Mike Henneman | 383 | 302 | 81 |
| 1988-06-28 | vs DET | 74 | L 1-6 | 43-31 | 2 | 37,103 | Rick Rhoden | Frank Tanana | Frank Tanana | Rick Rhoden | | 384 | 308 | 76 |
| 1988-06-29 | vs DET | 75 | W 7-3 | 44-31 | 2 | 33,064 | Richard Dotson | Walt Terrell | Steve Shields | Walt Terrell | | 391 | 311 | 80 |
| 1988-06-30 | @ CHA | 76 | W 5-3 | 45-31 | 2 | 18,168 | Tommy John | Dave LaPoint | Tommy John | Dave LaPoint | Dave Righetti | 396 | 314 | 82 |
| 1988-07-01 | @ CHA | 77 | L 1-2 | 45-32 | 2 | 19,798 | Ron Guidry | Jack McDowell | Bobby Thigpen | Steve Shields | | 397 | 316 | 81 |
| 1988-07-02 | @ CHA | 78 | W 4-0 | 46-32 | 2 | 23,350 | John Candelaria | Jerry Reuss | John Candelaria | Jerry Reuss | | 401 | 316 | 85 |
| 1988-07-03 | @ CHA | 79 | L 3-4 | 46-33 | 2 | 20,509 | Rick Rhoden | Bill Long | Jeff Bittiger | Cecilio Guante | | 404 | 320 | 84 |
| 1988-07-04 | @ TEX | 80 | W 13-2 | 47-33 | 2 | 41,093 | Charles Hudson | Charlie Hough | Charles Hudson | Charlie Hough | | 417 | 322 | 95 |
| 1988-07-05 | @ TEX | 81 | W 5-3 | 48-33 | 2 | 17,546 | Tommy John | Ray Hayward | Tommy John | Ray Hayward | Tim Stoddard | 422 | 325 | 97 |
| 1988-07-06 | @ TEX | 82 | L 2-4 | 48-34 | 2 | 20,324 | Ron Guidry | Jeff Russell | Jeff Russell | Ron Guidry | Mitch Williams | 424 | 329 | 95 |
| 1988-07-08 | vs KCA | 83 | L 0-4 | 48-35 | 2 | 34,038 | John Candelaria | Mark Gubicza | Mark Gubicza | John Candelaria | | 424 | 333 | 91 |
| 1988-07-09 | vs KCA | 84 | W 5-3 | 49-35 | 2 | 36,557 | Rick Rhoden | Ted Power | Rick Rhoden | Ted Power | Charles Hudson | 429 | 336 | 93 |
| 1988-07-10 | vs KCA | 85 | L 3-5 | 49-36 | 2 | 55,318 | Tommy John | Floyd Bannister | Rick Anderson | Tim Stoddard | Steve Farr | 432 | 341 | 91 |
| 1988-07-14 | vs CHA | 86 | W 7-5 | 50-36 | 2 | 28,284 | John Candelaria | Jerry Reuss | John Candelaria | Jerry Reuss | Cecilio Guante | 439 | 346 | 93 |
| 1988-07-15 | vs CHA | 87 | W 5-3 | 51-36 | 2 | 28,166 | Rick Rhoden | Jack McDowell | Rick Rhoden | Jack McDowell | Cecilio Guante | 444 | 349 | 95 |
| 1988-07-16 | vs CHA | 88 | L 4-7 | 51-37 | 2 | 48,102 | Tommy John | Melido Perez | Melido Perez | Tommy John | Bobby Thigpen | 448 | 356 | 92 |
| 1988-07-17 | vs CHA | 89 | W 7-3 | 52-37 | 2 | 38,750 | Ron Guidry | Dave LaPoint | Ron Guidry | Dave LaPoint | Tim Stoddard | 455 | 359 | 96 |
| 1988-07-18 | vs TEX | 90 | W 7-2 | 53-37 | 2 | 21,449 | Richard Dotson | Paul Kilgus | Richard Dotson | Paul Kilgus | | 462 | 361 | 101 |
| 1988-07-19 | vs TEX | 91 | L 2-7 | 53-38 | 2 | 27,456 | John Candelaria | Charlie Hough | Charlie Hough | John Candelaria | | 464 | 368 | 96 |
| 1988-07-21 | @ KCA | 92 | L 5-6 | 53-39 | 2 | 41,040 | Rick Rhoden | Mark Gubicza | Steve Farr | Cecilio Guante | | 469 | 374 | 95 |
| 1988-07-22 | @ KCA | 93 | W 9-8 | 54-39 | 2 | 40,011 | Tommy John | Ted Power | Neil Allen | Israel Sanchez | Dave Righetti | 478 | 382 | 96 |
| 1988-07-23 | @ KCA | 94 | L 5-6 | 54-40 | 2 | 41,377 | Ron Guidry | Floyd Bannister | Rick Anderson | Dave Righetti | Steve Farr | 483 | 388 | 95 |
| 1988-07-24 | @ KCA | 95 | W 10-8 | 55-40 | 2 | 38,591 | Richard Dotson | Bret Saberhagen | Neil Allen | Bret Saberhagen | Dave Righetti | 493 | 396 | 97 |
| 1988-07-25 | vs MIL | 96 | W 3-2 | 56-40 | 1 | 26,084 | John Candelaria | Teddy Higuera | John Candelaria | Teddy Higuera | | 496 | 398 | 98 |
| 1988-07-26 | vs MIL | 97 | W 3-2 | 57-40 | 1 | 20,549 | Rick Rhoden | Don August | Rick Rhoden | Don August | Dave Righetti | 499 | 400 | 99 |
| 1988-07-27 | vs MIL | 98 | W 16-3 | 58-40 | 1 | 28,869 | Tommy John | Chris Bosio | Tommy John | Chris Bosio | | 515 | 403 | 112 |
| 1988-07-28 | vs MIL | 99 | L 1-6 | 58-41 | 2 | 34,338 | Ron Guidry | Mike Birkbeck | Mike Birkbeck | Ron Guidry | Chuck Crim | 516 | 409 | 107 |
| 1988-07-29 | @ TOR | 100 | L 1-7 | 58-42 | 2 | 42,453 | Richard Dotson | Jeff Musselman | Jeff Musselman | Richard Dotson | | 517 | 416 | 101 |
| 1988-07-30 | @ TOR | 101 | W 3-1 | 59-42 | 2 | 45,457 | John Candelaria | Mike Flanagan | John Candelaria | Mike Flanagan | Dave Righetti | 520 | 417 | 103 |
| 1988-07-31 | @ TOR | 102 | W 6-3 | 60-42 | 2 | 41,401 | Rick Rhoden | Jimmy Key | Rick Rhoden | Jimmy Key | Dave Righetti | 526 | 420 | 106 |
| 1988-08-02 | @ MIL | 103 | L 5-11 | 60-43 | 3 | 24,640 | Tommy John | Mike Birkbeck | Mike Birkbeck | Tommy John | | 531 | 431 | 100 |
| 1988-08-03 | @ MIL | 104 | L 5-6 | 60-44 | 3 | 25,266 | Dave Eiland | Bill Wegman | Chuck Crim | Dave Righetti | Dan Plesac | 536 | 437 | 99 |
| 1988-08-05 | vs MIN | 105 | L 5-7 | 60-46 | 3 | 0 | Rick Rhoden | Freddie Toliver | Freddie Toliver | Rick Rhoden | Jeff Reardon | 541 | 444 | 97 |
| 1988-08-05 | vs MIN | 106 | L 2-11 | 60-46 | 3 | 37,451 | Lee Guetterman | Frank Viola | Frank Viola | Lee Guetterman | | 543 | 455 | 88 |
| 1988-08-06 | vs MIN | 107 | W 5-3 | 61-46 | 2 | 40,814 | Tommy John | Roy Smith | Steve Shields | Mark Portugal | Dave Righetti | 548 | 458 | 90 |
| 1988-08-07 | vs MIN | 108 | W 5-1 | 62-46 | 2 | 53,176 | Richard Dotson | Charlie Lea | Richard Dotson | Charlie Lea | | 553 | 459 | 94 |
| 1988-08-09 | vs TOR | 109 | L 3-6 | 62-47 | 3 | 30,089 | John Candelaria | Mike Flanagan | Mike Flanagan | John Candelaria | Duane Ward | 556 | 465 | 91 |
| 1988-08-10 | vs TOR | 110 | L 0-5 | 62-48 | 3 | 28,026 | Rick Rhoden | Jimmy Key | Jimmy Key | Rick Rhoden | Tom Henke | 556 | 470 | 86 |
| 1988-08-11 | vs TOR | 111 | L 5-6 | 62-49 | 3 | 30,347 | Dave Eiland | Dave Stieb | Duane Ward | Dave Righetti | | 561 | 476 | 85 |
| 1988-08-12 | @ MIN | 112 | W 6-4 | 63-49 | 3 | 52,230 | Tommy John | Charlie Lea | Steve Shields | Jeff Reardon | Dave Righetti | 567 | 480 | 87 |
| 1988-08-13 | @ MIN | 113 | L 2-12 | 63-50 | 3 | 51,963 | Richard Dotson | Roy Smith | Roy Smith | Richard Dotson | | 569 | 492 | 77 |
| 1988-08-14 | @ MIN | 114 | W 9-6 | 64-50 | 3 | 51,316 | John Candelaria | Freddie Toliver | John Candelaria | Freddie Toliver | | 578 | 498 | 80 |
| 1988-08-16 | vs CAL | 115 | L 6-15 | 64-51 | 3 | 30,214 | Rick Rhoden | Willie Fraser | Willie Fraser | Rick Rhoden | | 584 | 513 | 71 |
| 1988-08-17 | vs CAL | 116 | W 11-7 | 65-51 | 3 | 26,532 | Dave Eiland | Terry Clark | Scott Nielsen | Stew Cliburn | Dave Righetti | 595 | 520 | 75 |
| 1988-08-18 | vs CAL | 117 | L 1-7 | 65-52 | 3 | 26,044 | Tommy John | Chuck Finley | Chuck Finley | Tommy John | Greg Minton | 596 | 527 | 69 |
| 1988-08-19 | vs SEA | 118 | W 5-3 | 66-53 | 3 | 0 | John Candelaria | Terry Taylor | Dave Righetti | Mike Schooler | | 601 | 530 | 71 |
| 1988-08-19 | vs SEA | 119 | L 1-6 | 66-53 | 3 | 32,057 | Richard Dotson | Mike Moore | Mike Moore | Richard Dotson | | 602 | 536 | 66 |
| 1988-08-20 | vs SEA | 120 | L 5-9 | 66-54 | 3 | 39,086 | Scott Nielsen | Mike Campbell | Mike Campbell | Scott Nielsen | | 607 | 545 | 62 |
| 1988-08-21 | vs SEA | 121 | L 2-4 | 66-55 | 3 | 42,293 | Rick Rhoden | Scott Bankhead | Scott Bankhead | Rick Rhoden | Mike Schooler | 609 | 549 | 60 |
| 1988-08-22 | vs OAK | 122 | L 2-9 | 66-56 | 3 | 34,583 | Charles Hudson | Curt Young | Curt Young | Charles Hudson | | 611 | 558 | 53 |
| 1988-08-23 | vs OAK | 123 | W 5-4 | 67-56 | 3 | 32,250 | Tommy John | Bob Welch | Dave Righetti | Greg Cadaret | | 616 | 562 | 54 |
| 1988-08-24 | vs OAK | 124 | W 7-6 | 68-56 | 3 | 34,520 | John Candelaria | Dave Stewart | Cecilio Guante | Gene Nelson | | 623 | 568 | 55 |
| 1988-08-25 | @ MIL | 125 | L 1-4 | 68-57 | 3 | 14,847 | Richard Dotson | Teddy Higuera | Teddy Higuera | Richard Dotson | | 624 | 572 | 52 |
| 1988-08-26 | @ CAL | 126 | L 6-7 | 68-58 | 3 | 44,293 | Rick Rhoden | Willie Fraser | Bryan Harvey | Steve Shields | | 630 | 579 | 51 |
| 1988-08-27 | @ CAL | 127 | L 0-12 | 68-59 | 3 | 34,908 | Charles Hudson | Terry Clark | Terry Clark | Charles Hudson | | 630 | 591 | 39 |
| 1988-08-28 | @ CAL | 128 | L 2-13 | 68-60 | 3 | 40,406 | Tommy John | Chuck Finley | Chuck Finley | Tommy John | | 632 | 604 | 28 |
| 1988-08-29 | @ SEA | 129 | L 6-9 | 68-61 | 3 | 14,963 | Scott Nielsen | Mark Langston | Mark Langston | Scott Nielsen | | 638 | 613 | 25 |
| 1988-08-30 | @ SEA | 130 | L 1-7 | 68-62 | 3 | 13,065 | Richard Dotson | Mike Campbell | Mike Campbell | Richard Dotson | | 639 | 620 | 19 |
| 1988-08-31 | @ SEA | 131 | W 4-1 | 69-62 | 3 | 13,567 | Rick Rhoden | Scott Bankhead | Rick Rhoden | Scott Bankhead | | 643 | 621 | 22 |
| 1988-09-02 | @ OAK | 132 | W 4-1 | 70-62 | 3 | 36,465 | Tommy John | Curt Young | Tommy John | Curt Young | Dave Righetti | 647 | 622 | 25 |
| 1988-09-03 | @ OAK | 133 | L 4-5 | 70-63 | 3 | 43,074 | Ron Guidry | Bob Welch | Eric Plunk | Dale Mohorcic | Dennis Eckersley | 651 | 627 | 24 |
| 1988-09-04 | @ OAK | 134 | L 2-11 | 70-64 | 3 | 43,042 | Richard Dotson | Dave Stewart | Dave Stewart | Richard Dotson | | 653 | 638 | 15 |
| 1988-09-05 | vs CLE | 135 | W 7-2 | 71-64 | 3 | 27,884 | Rick Rhoden | Tom Candiotti | Rick Rhoden | Don Gordon | | 660 | 640 | 20 |
| 1988-09-06 | vs CLE | 136 | L 0-1 | 71-65 | 4 | 22,055 | Al Leiter | Greg Swindell | Greg Swindell | Al Leiter | | 660 | 641 | 19 |
| 1988-09-07 | vs CLE | 137 | L 4-5 | 71-66 | 4 | 30,023 | Tommy John | Rod Nichols | Rod Nichols | Tommy John | Doug Jones | 664 | 646 | 18 |
| 1988-09-08 | vs DET | 138 | W 7-4 | 72-66 | 3 | 27,589 | Ron Guidry | Ted Power | Hipolito Pena | Mike Henneman | | 671 | 650 | 21 |
| 1988-09-09 | vs DET | 139 | W 3-2 | 73-66 | 3 | 35,335 | Richard Dotson | Walt Terrell | Dale Mohorcic | Walt Terrell | | 674 | 652 | 22 |
| 1988-09-10 | vs DET | 140 | W 9-4 | 74-66 | 3 | 45,418 | Rick Rhoden | Jack Morris | Rick Rhoden | Jack Morris | | 683 | 656 | 27 |
| 1988-09-11 | vs DET | 141 | W 5-4 | 75-66 | 2 | 39,008 | Al Leiter | Doyle Alexander | Steve Shields | Guillermo Hernandez | | 688 | 660 | 28 |
| 1988-09-12 | @ CLE | 142 | L 6-8 | 75-67 | 3 | 11,426 | Tommy John | Greg Swindell | Greg Swindell | Tommy John | Doug Jones | 694 | 668 | 26 |
| 1988-09-13 | @ CLE | 143 | W 5-4 | 76-67 | 2 | 8,455 | Ron Guidry | Rod Nichols | Neil Allen | Scott Bailes | Dave Righetti | 699 | 672 | 27 |
| 1988-09-14 | @ CLE | 144 | W 7-5 | 77-67 | 2 | 12,478 | Richard Dotson | Rich Yett | Richard Dotson | Rich Yett | Dale Mohorcic | 706 | 677 | 29 |
| 1988-09-15 | @ BOS | 145 | W 5-3 | 78-67 | 2 | 35,320 | Rick Rhoden | Roger Clemens | Rick Rhoden | Roger Clemens | Dave Righetti | 711 | 680 | 31 |
| 1988-09-16 | @ BOS | 146 | L 4-7 | 78-68 | 2 | 35,226 | Al Leiter | Wes Gardner | Wes Gardner | Steve Shields | Lee Smith | 715 | 687 | 28 |
| 1988-09-17 | @ BOS | 147 | L 1-3 | 78-69 | 3 | 35,051 | Charles Hudson | Bruce Hurst | Bruce Hurst | Charles Hudson | | 716 | 690 | 26 |
| 1988-09-18 | @ BOS | 148 | L 4-9 | 78-70 | 4 | 35,146 | Ron Guidry | Mike Smithson | Mike Smithson | Ron Guidry | Lee Smith | 720 | 699 | 21 |
| 1988-09-19 | vs BAL | 149 | W 3-2 | 79-70 | 3 | 23,706 | Richard Dotson | Pete Harnisch | Richard Dotson | Pete Harnisch | Dave Righetti | 723 | 701 | 22 |
| 1988-09-20 | vs BAL | 150 | W 7-1 | 80-70 | 3 | 16,227 | Rick Rhoden | Jose Bautista | Rick Rhoden | Jose Bautista | | 730 | 702 | 28 |
| 1988-09-21 | vs BAL | 151 | W 3-2 | 81-70 | 3 | 21,343 | Tommy John | Jeff Ballard | Dale Mohorcic | Mark Thurmond | | 733 | 704 | 29 |
| 1988-09-23 | vs BOS | 152 | L 9-10 | 81-71 | 3 | 51,511 | Charles Hudson | Bruce Hurst | Dennis Lamp | Dale Mohorcic | Lee Smith | 742 | 714 | 28 |
| 1988-09-24 | vs BOS | 153 | W 5-4 | 82-71 | 2 | 51,392 | Richard Dotson | Mike Boddicker | Lee Guetterman | Lee Smith | | 747 | 718 | 29 |
| 1988-09-25 | vs BOS | 154 | L 0-6 | 82-72 | 4 | 54,774 | Rick Rhoden | Roger Clemens | Roger Clemens | Rick Rhoden | | 747 | 724 | 23 |
| 1988-09-26 | @ BAL | 155 | W 5-4 | 83-72 | 3 | 14,651 | Tommy John | Jeff Ballard | Steve Shields | Jay Tibbs | Dave Righetti | 752 | 728 | 24 |
| 1988-09-27 | @ BAL | 156 | W 5-1 | 84-72 | 2 | 21,600 | Ron Guidry | Curt Schilling | Ron Guidry | Curt Schilling | | 757 | 729 | 28 |
| 1988-09-28 | @ BAL | 157 | L 0-2 | 84-73 | 3 | 15,737 | Lee Guetterman | Bob Milacki | Bob Milacki | Lee Guetterman | | 757 | 731 | 26 |
| 1988-09-29 | @ BAL | 158 | W 5-1 | 85-73 | 3 | 38,958 | Richard Dotson | Mark Williamson | Richard Dotson | Mark Williamson | Dave Righetti | 762 | 732 | 30 |
| 1988-09-30 | @ DET | 159 | L 2-6 | 85-74 | 4 | 34,176 | Rick Rhoden | Jack Morris | Jack Morris | Rick Rhoden | | 764 | 738 | 26 |
| 1988-10-01 | @ DET | 160 | L 5-6 | 85-75 | 5 | 39,960 | Tommy John | Doyle Alexander | Mike Henneman | Neil Allen | | 769 | 744 | 25 |
| 1988-10-02 | @ DET | 161 | L 3-4 | 85-76 | 5 | 35,359 | Pat Clements | Frank Tanana | Paul Gibson | Dave Righetti | | 772 | 748 | 24 |