| 2004-04-05 | @ TOR | 1 | W 7-0 | 1-0 | 1 | 47,817 | Jason Johnson | Roy Halladay | Jason Johnson | Roy Halladay | | 7 | 0 | 7 |
| 2004-04-06 | @ TOR | 2 | W 7-3 | 2-0 | 1 | 21,003 | Mike Maroth | Miguel Batista | Mike Maroth | Miguel Batista | Nate Robertson | 14 | 3 | 11 |
| 2004-04-07 | @ TOR | 3 | W 6-3 | 3-0 | 1 | 13,100 | Jeremy Bonderman | Pat Hentgen | Jeremy Bonderman | Pat Hentgen | | 20 | 6 | 14 |
| 2004-04-08 | vs MIN | 4 | W 10-6 | 4-0 | 1 | 42,121 | Nate Cornejo | Carlos Silva | Nate Cornejo | Aaron Fultz | | 30 | 12 | 18 |
| 2004-04-10 | vs MIN | 5 | L 5-10 | 4-1 | 1 | 23,409 | Jason Johnson | Brad Radke | Brad Radke | Jason Johnson | | 35 | 22 | 13 |
| 2004-04-11 | vs MIN | 6 | W 6-5 | 5-1 | 1 | 12,138 | Mike Maroth | Johan Santana | Steve Colyer | Joe Roa | | 41 | 27 | 14 |
| 2004-04-13 | vs TOR | 7 | L 5-7 | 5-2 | 1 | 8,804 | Jeremy Bonderman | Pat Hentgen | Terry Adams | Danny Patterson | Justin Speier | 46 | 34 | 12 |
| 2004-04-14 | vs TOR | 8 | W 5-3 | 6-2 | 1 | 15,129 | Nate Robertson | Ted Lilly | Nate Robertson | Ted Lilly | Danny Patterson | 51 | 37 | 14 |
| 2004-04-15 | vs TOR | 9 | L 0-11 | 6-3 | 2 | 17,572 | Jason Johnson | Roy Halladay | Roy Halladay | Jason Johnson | | 51 | 48 | 3 |
| 2004-04-16 | @ CLE | 10 | L 3-10 | 6-4 | 2 | 18,507 | Nate Cornejo | CC Sabathia | CC Sabathia | Nate Cornejo | | 54 | 58 | -4 |
| 2004-04-17 | @ CLE | 11 | W 6-1 | 7-4 | 2 | 18,955 | Mike Maroth | Jason Davis | Mike Maroth | Jason Davis | | 60 | 59 | 1 |
| 2004-04-18 | @ CLE | 12 | L 7-9 | 7-5 | 3 | 19,240 | Jeremy Bonderman | Cliff Lee | Cliff Lee | Jeremy Bonderman | David Riske | 67 | 68 | -1 |
| 2004-04-19 | @ CLE | 13 | W 10-4 | 8-5 | 3 | 13,650 | Nate Robertson | Jeff D'Amico | Al Levine | Rafael Betancourt | | 77 | 72 | 5 |
| 2004-04-20 | @ MIN | 14 | L 4-6 | 8-6 | 3 | 15,079 | Jason Johnson | Carlos Silva | Carlos Silva | Jason Johnson | Joe Nathan | 81 | 78 | 3 |
| 2004-04-21 | @ MIN | 15 | W 11-8 | 9-6 | 2 | 15,158 | Nate Cornejo | Brad Radke | Al Levine | Brad Radke | Ugueth Urbina | 92 | 86 | 6 |
| 2004-04-22 | @ MIN | 16 | L 3-4 | 9-7 | 3 | 14,857 | Mike Maroth | Johan Santana | Johan Santana | Mike Maroth | Joe Nathan | 95 | 90 | 5 |
| 2004-04-23 | vs CLE | 17 | W 17-3 | 10-7 | 3 | 22,008 | Jeremy Bonderman | Jason Davis | Jeremy Bonderman | Jason Davis | Esteban Yan | 112 | 93 | 19 |
| 2004-04-24 | vs CLE | 18 | W 5-2 | 11-7 | 2 | 20,913 | Nate Robertson | Cliff Lee | Ugueth Urbina | Scott Stewart | | 117 | 95 | 22 |
| 2004-04-25 | vs CLE | 19 | L 2-3 | 11-8 | 3 | 17,253 | Jason Johnson | Jake Westbrook | Jake Westbrook | Jason Johnson | | 119 | 98 | 21 |
| 2004-04-27 | vs ANA | 20 | L 4-10 | 11-9 | 3 | 18,208 | Nate Cornejo | John Lackey | John Lackey | Nate Cornejo | Scot Shields | 123 | 108 | 15 |
| 2004-04-28 | vs ANA | 21 | W 10-2 | 12-9 | 3 | 17,175 | Mike Maroth | Bartolo Colon | Mike Maroth | Bartolo Colon | | 133 | 110 | 23 |
| 2004-04-29 | vs ANA | 22 | L 3-12 | 12-10 | 3 | 20,678 | Nate Robertson | Jarrod Washburn | Jarrod Washburn | Nate Robertson | | 136 | 122 | 14 |
| 2004-04-30 | vs SEA | 23 | L 1-3 | 12-11 | 3 | 19,989 | Jason Johnson | Freddy Garcia | Mike Myers | Al Levine | Eddie Guardado | 137 | 125 | 12 |
| 2004-05-01 | vs SEA | 24 | W 4-2 | 13-11 | 3 | 16,407 | Jeremy Bonderman | Ryan Franklin | Jeremy Bonderman | Ryan Franklin | Ugueth Urbina | 141 | 127 | 14 |
| 2004-05-02 | vs SEA | 25 | L 2-12 | 13-12 | 3 | 13,720 | Nate Cornejo | Gil Meche | Gil Meche | Nate Cornejo | | 143 | 139 | 4 |
| 2004-05-03 | @ ANA | 26 | L 9-11 | 13-13 | 3 | 33,683 | Mike Maroth | Bartolo Colon | Kevin Gregg | Al Levine | Troy Percival | 152 | 150 | 2 |
| 2004-05-04 | @ ANA | 27 | L 4-11 | 13-14 | 3 | 34,920 | Nate Robertson | Jarrod Washburn | Jarrod Washburn | Nate Robertson | | 156 | 161 | -5 |
| 2004-05-05 | @ ANA | 28 | L 3-6 | 13-15 | 3 | 39,827 | Jason Johnson | Kelvim Escobar | Kelvim Escobar | Jason Johnson | Troy Percival | 159 | 167 | -8 |
| 2004-05-07 | @ TEX | 29 | W 8-7 | 14-15 | 3 | 41,095 | Jeremy Bonderman | Joaquin Benoit | Al Levine | Erasmo Ramirez | Ugueth Urbina | 167 | 174 | -7 |
| 2004-05-08 | @ TEX | 30 | L 15-16 | 14-16 | 3 | 45,017 | Mike Maroth | R.A. Dickey | Francisco Cordero | Ugueth Urbina | | 182 | 190 | -8 |
| 2004-05-09 | @ TEX | 31 | W 5-3 | 15-16 | 3 | 25,034 | Nate Robertson | Kenny Rogers | Nate Robertson | Kenny Rogers | Ugueth Urbina | 187 | 193 | -6 |
| 2004-05-11 | vs OAK | 32 | L 4-5 | 15-17 | 3 | 15,859 | Jason Johnson | Barry Zito | Justin Duchscherer | Danny Patterson | Jim Mecir | 191 | 198 | -7 |
| 2004-05-12 | vs OAK | 33 | L 1-2 | 15-18 | 3 | 16,693 | Jeremy Bonderman | Rich Harden | Rich Harden | Jeremy Bonderman | Arthur Rhodes | 192 | 200 | -8 |
| 2004-05-13 | vs OAK | 34 | W 3-1 | 16-18 | 3 | 21,712 | Mike Maroth | Mark Redman | Mike Maroth | Mark Redman | Ugueth Urbina | 195 | 201 | -6 |
| 2004-05-14 | vs TEX | 35 | W 7-1 | 17-18 | 3 | 22,449 | Gary Knotts | Joaquin Benoit | Gary Knotts | Joaquin Benoit | Esteban Yan | 202 | 202 | 0 |
| 2004-05-15 | vs TEX | 36 | L 1-6 | 17-19 | 3 | 26,120 | Nate Robertson | Kenny Rogers | Kenny Rogers | Nate Robertson | | 203 | 208 | -5 |
| 2004-05-16 | vs TEX | 37 | W 3-1 | 18-19 | 3 | 21,615 | Jason Johnson | Ryan Drese | Jason Johnson | Ryan Drese | Ugueth Urbina | 206 | 209 | -3 |
| 2004-05-18 | @ OAK | 38 | W 5-1 | 19-19 | 3 | 11,842 | Jeremy Bonderman | Rich Harden | Jeremy Bonderman | Rich Harden | | 211 | 210 | 1 |
| 2004-05-19 | @ OAK | 39 | L 2-6 | 19-20 | 3 | 20,477 | Mike Maroth | Mark Redman | Mark Redman | Mike Maroth | | 213 | 216 | -3 |
| 2004-05-20 | @ OAK | 40 | L 2-3 | 19-21 | 3 | 20,808 | Gary Knotts | Tim Hudson | Tim Hudson | Jamie Walker | Arthur Rhodes | 215 | 219 | -4 |
| 2004-05-21 | @ SEA | 41 | W 5-0 | 20-21 | 3 | 39,102 | Nate Robertson | Gil Meche | Nate Robertson | Gil Meche | | 220 | 219 | 1 |
| 2004-05-22 | @ SEA | 42 | W 8-4 | 21-21 | 3 | 42,565 | Jason Johnson | Joel Pineiro | Jason Johnson | J.J. Putz | | 228 | 223 | 5 |
| 2004-05-23 | @ SEA | 43 | L 1-3 | 21-22 | 3 | 44,850 | Jeremy Bonderman | Freddy Garcia | Freddy Garcia | Jeremy Bonderman | Eddie Guardado | 229 | 226 | 3 |
| 2004-05-25 | @ KCA | 44 | L 3-4 | 21-23 | 3 | 14,297 | Mike Maroth | Jimmy Gobble | Jason Grimsley | Mike Maroth | Jeremy Affeldt | 232 | 230 | 2 |
| 2004-05-26 | @ KCA | 45 | L 3-7 | 21-24 | 3 | 19,534 | Gary Knotts | Darrell May | Darrell May | Gary Knotts | Jeremy Affeldt | 235 | 237 | -2 |
| 2004-05-27 | @ KCA | 46 | W 17-7 | 22-24 | 3 | 15,475 | Nate Robertson | Brian Anderson | Nate Robertson | Brian Anderson | | 252 | 244 | 8 |
| 2004-05-28 | vs BAL | 47 | L 5-7 | 22-25 | 3 | 23,298 | Jason Johnson | Eric DuBose | Eric DuBose | Jason Johnson | Jorge Julio | 257 | 251 | 6 |
| 2004-05-29 | vs BAL | 48 | L 4-8 | 22-26 | 3 | 30,440 | Jeremy Bonderman | Daniel Cabrera | Daniel Cabrera | Jeremy Bonderman | John Parrish | 261 | 259 | 2 |
| 2004-05-30 | vs BAL | 49 | L 3-7 | 22-27 | 4 | 25,337 | Mike Maroth | Erik Bedard | Buddy Groom | Ugueth Urbina | | 264 | 266 | -2 |
| 2004-05-31 | vs KCA | 50 | W 8-4 | 23-27 | 3 | 12,982 | Gary Knotts | Darrell May | Gary Knotts | Darrell May | | 272 | 270 | 2 |
| 2004-06-01 | vs KCA | 51 | L 3-5 | 23-28 | 3 | 12,685 | Nate Robertson | Chris George | Jason Grimsley | Esteban Yan | Jeremy Affeldt | 275 | 275 | 0 |
| 2004-06-02 | vs KCA | 52 | W 2-0 | 24-28 | 3 | 12,186 | Jason Johnson | Zack Greinke | Jason Johnson | Zack Greinke | Ugueth Urbina | 277 | 275 | 2 |
| 2004-06-03 | vs KCA | 53 | L 6-9 | 24-29 | 3 | 16,711 | Jeremy Bonderman | Dennys Reyes | Dennys Reyes | Jeremy Bonderman | Jeremy Affeldt | 283 | 284 | -1 |
| 2004-06-04 | @ MIN | 54 | L 2-3 | 24-30 | 3 | 15,391 | Mike Maroth | Kyle Lohse | Joe Nathan | Jamie Walker | | 285 | 287 | -2 |
| 2004-06-05 | @ MIN | 55 | W 6-0 | 25-30 | 3 | 17,573 | Gary Knotts | Seth Greisinger | Gary Knotts | Seth Greisinger | | 291 | 287 | 4 |
| 2004-06-06 | @ MIN | 56 | L 5-6 | 25-31 | 4 | 20,378 | Nate Robertson | Carlos Silva | J.C. Romero | Esteban Yan | Joe Nathan | 296 | 293 | 3 |
| 2004-06-08 | vs ATL | 57 | L 3-4 | 25-32 | 4 | 19,062 | Jason Johnson | Mike Hampton | Chris Reitsma | Danny Patterson | John Smoltz | 299 | 297 | 2 |
| 2004-06-09 | vs ATL | 58 | W 4-2 | 26-32 | 4 | 20,577 | Jeremy Bonderman | John Thomson | Craig Dingman | John Thomson | Ugueth Urbina | 303 | 299 | 4 |
| 2004-06-10 | vs ATL | 59 | W 7-4 | 27-32 | 3 | 21,166 | Mike Maroth | Russ Ortiz | Mike Maroth | Antonio Alfonseca | Ugueth Urbina | 310 | 303 | 7 |
| 2004-06-11 | vs FLO | 60 | W 8-4 | 28-32 | 3 | 27,184 | Gary Knotts | Tommy Phelps | Gary Knotts | Tommy Phelps | | 318 | 307 | 11 |
| 2004-06-12 | vs FLO | 61 | W 6-2 | 29-32 | 3 | 38,524 | Nate Robertson | Brad Penny | Nate Robertson | Brad Penny | Ugueth Urbina | 324 | 309 | 15 |
| 2004-06-13 | vs FLO | 62 | L 2-9 | 29-33 | 4 | 27,334 | Jason Johnson | Dontrelle Willis | Dontrelle Willis | Jason Johnson | | 326 | 318 | 8 |
| 2004-06-15 | @ PHI | 63 | W 10-3 | 30-33 | 4 | 39,555 | Jeremy Bonderman | Brian Powell | Jeremy Bonderman | Brian Powell | | 336 | 321 | 15 |
| 2004-06-17 | @ PHI | 64 | L 2-6 | 31-34 | 4 | 44,551 | Mike Maroth | Brett Myers | Brett Myers | Mike Maroth | | 338 | 327 | 11 |
| 2004-06-17 | @ PHI | 65 | W 5-4 | 31-34 | 4 | 39,674 | Gary Knotts | Kevin Millwood | Ugueth Urbina | Ryan Madson | Danny Patterson | 343 | 331 | 12 |
| 2004-06-18 | @ NYN | 66 | L 2-3 | 31-35 | 4 | 36,141 | Nate Robertson | Tom Glavine | Braden Looper | Danny Patterson | | 345 | 334 | 11 |
| 2004-06-19 | @ NYN | 67 | L 3-4 | 31-36 | 4 | 36,925 | Jason Johnson | Al Leiter | Braden Looper | Craig Dingman | | 348 | 338 | 10 |
| 2004-06-20 | @ NYN | 68 | L 1-6 | 31-37 | 4 | 39,446 | Jeremy Bonderman | Steve Trachsel | Steve Trachsel | Jeremy Bonderman | | 349 | 344 | 5 |
| 2004-06-22 | @ KCA | 69 | L 1-8 | 31-38 | 4 | 16,276 | Mike Maroth | Jimmy Gobble | Jimmy Gobble | Mike Maroth | Nate Field | 350 | 352 | -2 |
| 2004-06-23 | @ KCA | 70 | L 3-7 | 31-39 | 4 | 18,493 | Gary Knotts | Darrell May | Darrell May | Gary Knotts | | 353 | 359 | -6 |
| 2004-06-24 | @ KCA | 71 | W 12-3 | 32-39 | 4 | 18,172 | Nate Robertson | Chris George | Nate Robertson | Chris George | | 365 | 362 | 3 |
| 2004-06-25 | vs ARI | 72 | W 2-1 | 33-39 | 4 | 32,573 | Jason Johnson | Brandon Webb | Jason Johnson | Brandon Webb | Ugueth Urbina | 367 | 363 | 4 |
| 2004-06-26 | vs ARI | 73 | W 7-6 | 34-39 | 4 | 33,579 | Jeremy Bonderman | Casey Fossum | Ugueth Urbina | Brandon Villafuerte | | 374 | 369 | 5 |
| 2004-06-27 | vs ARI | 74 | W 9-5 | 35-39 | 4 | 32,751 | Mike Maroth | Steve Sparks | Jamie Walker | Brandon Villafuerte | | 383 | 374 | 9 |
| 2004-06-29 | vs CLE | 75 | W 9-7 | 36-39 | 4 | 30,457 | Gary Knotts | Jake Westbrook | Craig Dingman | Jose Jimenez | | 392 | 381 | 11 |
| 2004-06-30 | vs CLE | 76 | W 12-5 | 37-39 | 4 | 27,665 | Nate Robertson | Jason Davis | Nate Robertson | Jason Davis | | 404 | 386 | 18 |
| 2004-07-01 | vs CLE | 77 | L 6-7 | 37-40 | 4 | 25,159 | Jason Johnson | Cliff Lee | David Riske | Ugueth Urbina | Rick White | 410 | 393 | 17 |
| 2004-07-02 | @ COL | 78 | L 8-9 | 37-41 | 4 | 47,585 | Jeremy Bonderman | Joe Kennedy | Shawn Chacon | Jamie Walker | | 418 | 402 | 16 |
| 2004-07-03 | @ COL | 79 | L 6-11 | 37-42 | 4 | 48,131 | Mike Maroth | Jason Jennings | Jason Jennings | Mike Maroth | | 424 | 413 | 11 |
| 2004-07-04 | @ COL | 80 | L 8-10 | 37-43 | 4 | 26,944 | Gary Knotts | Shawn Estes | Adam Bernero | Gary Knotts | Shawn Chacon | 432 | 423 | 9 |
| 2004-07-05 | @ NYA | 81 | L 3-10 | 37-44 | 4 | 52,608 | Nate Robertson | Jon Lieber | Jon Lieber | Nate Robertson | | 435 | 433 | 2 |
| 2004-07-06 | @ NYA | 82 | W 9-1 | 38-44 | 4 | 41,772 | Jason Johnson | Mike Mussina | Jason Johnson | Mike Mussina | | 444 | 434 | 10 |
| 2004-07-07 | @ NYA | 83 | W 10-8 | 39-44 | 4 | 50,338 | Jeremy Bonderman | Brad Halsey | Jeremy Bonderman | Brad Halsey | Ugueth Urbina | 454 | 442 | 12 |
| 2004-07-08 | @ MIN | 84 | L 1-7 | 39-45 | 4 | 14,087 | Mike Maroth | Terry Mulholland | Grant Balfour | Mike Maroth | | 455 | 449 | 6 |
| 2004-07-09 | @ MIN | 85 | W 5-3 | 40-45 | 4 | 22,678 | Gary Knotts | Carlos Silva | Gary Knotts | Carlos Silva | Ugueth Urbina | 460 | 452 | 8 |
| 2004-07-10 | @ MIN | 86 | W 4-2 | 41-45 | 4 | 26,646 | Nate Robertson | Brad Radke | Nate Robertson | Brad Radke | Ugueth Urbina | 464 | 454 | 10 |
| 2004-07-11 | @ MIN | 87 | W 2-0 | 42-45 | 4 | 21,618 | Jason Johnson | Johan Santana | Jason Johnson | Johan Santana | | 466 | 454 | 12 |
| 2004-07-15 | vs NYA | 88 | L 1-5 | 42-46 | 4 | 38,902 | Jeremy Bonderman | Jose Contreras | Jose Contreras | Jeremy Bonderman | | 467 | 459 | 8 |
| 2004-07-16 | vs NYA | 89 | W 8-0 | 43-46 | 4 | 40,918 | Mike Maroth | Javier Vazquez | Mike Maroth | Javier Vazquez | | 475 | 459 | 16 |
| 2004-07-17 | vs NYA | 90 | L 3-5 | 43-47 | 4 | 41,857 | Gary Knotts | Orlando Hernandez | Orlando Hernandez | Gary Knotts | Mariano Rivera | 478 | 464 | 14 |
| 2004-07-18 | vs NYA | 91 | W 4-2 | 44-47 | 4 | 40,132 | Nate Robertson | Jon Lieber | Nate Robertson | Jon Lieber | Ugueth Urbina | 482 | 466 | 16 |
| 2004-07-19 | vs MIN | 92 | L 1-3 | 44-48 | 4 | 21,369 | Jason Johnson | Terry Mulholland | Terry Mulholland | Jason Johnson | Joe Nathan | 483 | 469 | 14 |
| 2004-07-20 | vs MIN | 93 | L 4-5 | 44-49 | 4 | 23,227 | Jeremy Bonderman | Kyle Lohse | Grant Balfour | Ugueth Urbina | Joe Nathan | 487 | 474 | 13 |
| 2004-07-21 | vs KCA | 94 | W 4-2 | 45-49 | 4 | 17,607 | Mike Maroth | Darrell May | Mike Maroth | Darrell May | Jamie Walker | 491 | 476 | 15 |
| 2004-07-22 | vs KCA | 95 | L 7-13 | 45-50 | 4 | 24,746 | Gary Knotts | Jimmy Gobble | Jimmy Gobble | Gary Knotts | | 498 | 489 | 9 |
| 2004-07-23 | @ CHA | 96 | L 4-6 | 45-51 | 4 | 32,930 | Nate Robertson | Esteban Loaiza | Esteban Loaiza | Nate Robertson | Shingo Takatsu | 502 | 495 | 7 |
| 2004-07-24 | @ CHA | 97 | L 6-7 | 45-52 | 4 | 38,055 | Jason Johnson | Scott Schoeneweis | Damaso Marte | Ugueth Urbina | | 508 | 502 | 6 |
| 2004-07-25 | @ CHA | 98 | W 9-2 | 46-52 | 4 | 26,716 | Jeremy Bonderman | Jon Garland | Wil Ledezma | Jon Garland | | 517 | 504 | 13 |
| 2004-07-26 | @ CLE | 99 | W 13-4 | 47-52 | 4 | 18,359 | Mike Maroth | Cliff Lee | Mike Maroth | Cliff Lee | | 530 | 508 | 22 |
| 2004-07-27 | @ CLE | 100 | L 6-10 | 47-53 | 4 | 19,090 | Gary Knotts | CC Sabathia | CC Sabathia | Gary Knotts | | 536 | 518 | 18 |
| 2004-07-28 | @ CLE | 101 | L 4-5 | 47-54 | 4 | 23,213 | Nate Robertson | Scott Elarton | Scott Elarton | Jamie Walker | Bob Wickman | 540 | 523 | 17 |
| 2004-07-29 | vs CHA | 102 | W 3-2 | 48-54 | 4 | 26,110 | Jason Johnson | Scott Schoeneweis | Jason Johnson | Scott Schoeneweis | Ugueth Urbina | 543 | 525 | 18 |
| 2004-07-30 | vs CHA | 103 | W 5-4 | 49-54 | 4 | 34,732 | Wil Ledezma | Jon Garland | Esteban Yan | Damaso Marte | Ugueth Urbina | 548 | 529 | 19 |
| 2004-07-31 | vs CHA | 104 | W 3-2 | 50-54 | 4 | 40,471 | Mike Maroth | Mark Buehrle | Ugueth Urbina | Cliff Politte | | 551 | 531 | 20 |
| 2004-08-01 | vs CHA | 105 | L 4-6 | 50-55 | 4 | 34,279 | Jeremy Bonderman | Freddy Garcia | Freddy Garcia | Jeremy Bonderman | Shingo Takatsu | 555 | 537 | 18 |
| 2004-08-03 | vs TEX | 106 | L 4-5 | 50-56 | 4 | 19,894 | Nate Robertson | Kenny Rogers | Frank Francisco | Nate Robertson | Francisco Cordero | 559 | 542 | 17 |
| 2004-08-04 | vs TEX | 107 | L 0-8 | 50-57 | 4 | 18,857 | Jason Johnson | Michael Bacsik | Michael Bacsik | Jason Johnson | | 559 | 550 | 9 |
| 2004-08-05 | vs TEX | 108 | L 1-2 | 50-58 | 4 | 25,710 | Wil Ledezma | Ryan Drese | Ryan Drese | Esteban Yan | Francisco Cordero | 560 | 552 | 8 |
| 2004-08-06 | vs BOS | 109 | W 4-3 | 51-58 | 4 | 40,674 | Mike Maroth | Derek Lowe | Roberto Novoa | Derek Lowe | Ugueth Urbina | 564 | 555 | 9 |
| 2004-08-07 | vs BOS | 110 | L 4-7 | 51-59 | 4 | 42,607 | Jeremy Bonderman | Pedro Martinez | Pedro Martinez | Jeremy Bonderman | | 568 | 562 | 6 |
| 2004-08-08 | vs BOS | 111 | L 9-11 | 51-60 | 4 | 40,098 | Nate Robertson | Tim Wakefield | Tim Wakefield | Nate Robertson | Keith Foulke | 577 | 573 | 4 |
| 2004-08-10 | @ OAK | 112 | L 4-5 | 51-61 | 4 | 20,315 | Jason Johnson | Barry Zito | Barry Zito | Jason Johnson | Octavio Dotel | 581 | 578 | 3 |
| 2004-08-11 | @ OAK | 113 | W 11-3 | 52-61 | 4 | 25,781 | Wil Ledezma | Mark Redman | Wil Ledezma | Mark Redman | | 592 | 581 | 11 |
| 2004-08-12 | @ OAK | 114 | W 5-3 | 53-61 | 4 | 17,963 | Mike Maroth | Tim Hudson | Mike Maroth | Justin Duchscherer | Ugueth Urbina | 597 | 584 | 13 |
| 2004-08-13 | @ ANA | 115 | W 5-3 | 54-61 | 4 | 43,580 | Jeremy Bonderman | John Lackey | Esteban Yan | Troy Percival | Ugueth Urbina | 602 | 587 | 15 |
| 2004-08-14 | @ ANA | 116 | L 8-11 | 54-62 | 4 | 43,545 | Nate Robertson | Ramon Ortiz | Kevin Gregg | Roberto Novoa | Francisco Rodriguez | 610 | 598 | 12 |
| 2004-08-15 | @ ANA | 117 | L 2-3 | 54-63 | 4 | 42,850 | Jason Johnson | Aaron Sele | Scot Shields | Jason Johnson | Troy Percival | 612 | 601 | 11 |
| 2004-08-17 | @ CHA | 118 | W 11-8 | 55-63 | 4 | 19,856 | Mike Maroth | Freddy Garcia | Mike Maroth | Freddy Garcia | Ugueth Urbina | 623 | 609 | 14 |
| 2004-08-18 | @ CHA | 119 | L 2-9 | 55-64 | 4 | 21,381 | Jeremy Bonderman | Jose Contreras | Jose Contreras | Jeremy Bonderman | | 625 | 618 | 7 |
| 2004-08-19 | @ CHA | 120 | W 8-4 | 56-64 | 4 | 24,554 | Wil Ledezma | Jon Garland | Wil Ledezma | Jon Garland | Gary Knotts | 633 | 622 | 11 |
| 2004-08-20 | vs SEA | 121 | W 8-3 | 57-64 | 4 | 32,791 | Nate Robertson | Ron Villone | Nate Robertson | Ron Villone | | 641 | 625 | 16 |
| 2004-08-21 | vs SEA | 122 | W 11-10 | 58-64 | 4 | 36,817 | Jason Johnson | Jamie Moyer | Jamie Walker | Scott Atchison | | 652 | 635 | 17 |
| 2004-08-22 | vs SEA | 123 | L 3-5 | 58-65 | 4 | 33,652 | Mike Maroth | Gil Meche | Gil Meche | Mike Maroth | J.J. Putz | 655 | 640 | 15 |
| 2004-08-23 | vs CHA | 124 | W 7-0 | 59-65 | 4 | 25,220 | Jeremy Bonderman | Jose Contreras | Jeremy Bonderman | Jose Contreras | | 662 | 640 | 22 |
| 2004-08-24 | vs CHA | 125 | L 5-9 | 59-66 | 4 | 24,584 | Wil Ledezma | Jon Garland | Jon Garland | Wil Ledezma | | 667 | 649 | 18 |
| 2004-08-25 | vs CHA | 126 | W 5-4 | 60-66 | 4 | 23,254 | Nate Robertson | Mark Buehrle | Nate Robertson | Mark Buehrle | | 672 | 653 | 19 |
| 2004-08-26 | @ BOS | 127 | L 1-4 | 60-67 | 4 | 35,153 | Jason Johnson | Bronson Arroyo | Bronson Arroyo | Jason Johnson | Keith Foulke | 673 | 657 | 16 |
| 2004-08-27 | @ BOS | 128 | L 3-5 | 60-68 | 4 | 35,018 | Mike Maroth | Derek Lowe | Derek Lowe | Mike Maroth | Curt Leskanic | 676 | 662 | 14 |
| 2004-08-28 | @ BOS | 129 | L 1-5 | 60-69 | 4 | 35,032 | Jeremy Bonderman | Pedro Martinez | Pedro Martinez | Jeremy Bonderman | | 677 | 667 | 10 |
| 2004-08-29 | @ BOS | 130 | L 1-6 | 60-70 | 4 | 34,268 | Wil Ledezma | Tim Wakefield | Tim Wakefield | Wil Ledezma | | 678 | 673 | 5 |
| 2004-08-30 | @ KCA | 131 | W 9-1 | 61-70 | 4 | 19,429 | Nate Robertson | Mike Wood | Nate Robertson | Mike Wood | | 687 | 674 | 13 |
| 2004-08-31 | @ KCA | 132 | L 8-9 | 61-71 | 4 | 19,471 | Jason Johnson | Brian Anderson | Jeremy Affeldt | Ugueth Urbina | | 695 | 683 | 12 |
| 2004-09-01 | @ KCA | 133 | L 0-1 | 61-72 | 4 | 19,039 | Mike Maroth | Zack Greinke | Zack Greinke | Mike Maroth | Jeremy Affeldt | 695 | 684 | 11 |
| 2004-09-03 | @ TBA | 134 | W 4-2 | 62-72 | 4 | 11,631 | Jeremy Bonderman | Scott Kazmir | Jeremy Bonderman | Scott Kazmir | Esteban Yan | 699 | 686 | 13 |
| 2004-09-06 | vs KCA | 135 | W 7-3 | 63-72 | 4 | 21,516 | Wil Ledezma | Denny Bautista | Wil Ledezma | Denny Bautista | Gary Knotts | 706 | 689 | 17 |
| 2004-09-07 | vs KCA | 136 | L 2-6 | 63-73 | 4 | 17,462 | Nate Robertson | Brian Anderson | Jimmy Serrano | Nate Robertson | | 708 | 695 | 13 |
| 2004-09-09 | vs KCA | 137 | L 5-26 | 64-74 | 4 | 0 | Jason Johnson | Zack Greinke | Zack Greinke | Jason Johnson | | 713 | 721 | -8 |
| 2004-09-09 | vs KCA | 138 | W 8-0 | 64-74 | 4 | 20,442 | Jeremy Bonderman | Darrell May | Jeremy Bonderman | Darrell May | | 721 | 721 | 0 |
| 2004-09-10 | vs MIN | 139 | L 1-4 | 64-75 | 4 | 27,391 | Mike Maroth | Carlos Silva | Carlos Silva | Mike Maroth | Joe Nathan | 722 | 725 | -3 |
| 2004-09-11 | vs MIN | 140 | L 2-3 | 64-76 | 4 | 28,931 | Gary Knotts | Kyle Lohse | Jesse Crain | Al Levine | Joe Nathan | 724 | 728 | -4 |
| 2004-09-12 | vs MIN | 141 | L 5-8 | 64-77 | 4 | 23,208 | Nate Robertson | Terry Mulholland | Terry Mulholland | Nate Robertson | Joe Nathan | 729 | 736 | -7 |
| 2004-09-13 | vs MIN | 142 | L 3-5 | 64-78 | 4 | 9,962 | Jason Johnson | Brad Radke | Brad Radke | Jason Johnson | Joe Nathan | 732 | 741 | -9 |
| 2004-09-14 | @ CLE | 143 | W 11-3 | 65-78 | 4 | 16,489 | Jeremy Bonderman | Kyle Denney | Jeremy Bonderman | Kyle Denney | | 743 | 744 | -1 |
| 2004-09-15 | @ CLE | 144 | L 3-5 | 65-79 | 4 | 15,411 | Mike Maroth | Scott Elarton | Bob Howry | Esteban Yan | Bob Wickman | 746 | 749 | -3 |
| 2004-09-16 | @ CLE | 145 | W 6-4 | 66-79 | 4 | 15,943 | Gary Knotts | CC Sabathia | Jamie Walker | CC Sabathia | Esteban Yan | 752 | 753 | -1 |
| 2004-09-17 | @ CHA | 146 | W 11-10 | 67-79 | 4 | 23,132 | Nate Robertson | Jason Grilli | Esteban Yan | Shingo Takatsu | John Ennis | 763 | 763 | 0 |
| 2004-09-18 | @ CHA | 147 | L 8-9 | 67-80 | 4 | 23,533 | Jason Johnson | Jose Contreras | Damaso Marte | Al Levine | | 771 | 772 | -1 |
| 2004-09-19 | @ CHA | 148 | L 1-6 | 67-81 | 4 | 19,269 | Jeremy Bonderman | Freddy Garcia | Freddy Garcia | Jeremy Bonderman | | 772 | 778 | -6 |
| 2004-09-20 | vs CLE | 149 | W 3-1 | 68-81 | 4 | 13,820 | Mike Maroth | Scott Elarton | Mike Maroth | Scott Elarton | Esteban Yan | 775 | 779 | -4 |
| 2004-09-21 | vs CLE | 150 | L 7-8 | 68-82 | 4 | 11,351 | Gary Knotts | Francisco Cruceta | Bob Howry | Esteban Yan | Bob Wickman | 782 | 787 | -5 |
| 2004-09-22 | vs CLE | 151 | L 6-7 | 68-83 | 4 | 16,360 | Nate Robertson | Jake Westbrook | Jake Westbrook | Wil Ledezma | | 788 | 794 | -6 |
| 2004-09-24 | @ BAL | 152 | L 5-7 | 68-84 | 4 | 25,846 | Jason Johnson | Bruce Chen | John Parrish | Esteban Yan | | 793 | 801 | -8 |
| 2004-09-25 | @ BAL | 153 | L 0-3 | 68-85 | 4 | 29,598 | Jeremy Bonderman | Matt Riley | Matt Riley | Jeremy Bonderman | B.J. Ryan | 793 | 804 | -11 |
| 2004-09-26 | @ BAL | 154 | L 0-5 | 68-86 | 4 | 41,178 | Mike Maroth | Rodrigo Lopez | Rodrigo Lopez | Mike Maroth | | 793 | 809 | -16 |
| 2004-09-27 | vs CHA | 155 | W 4-2 | 69-86 | 4 | 12,495 | Gary Knotts | Jason Grilli | Gary Knotts | Jason Grilli | Esteban Yan | 797 | 811 | -14 |
| 2004-09-28 | vs CHA | 156 | W 6-4 | 70-86 | 4 | 13,860 | Nate Robertson | Jose Contreras | Franklyn German | Neal Cotts | Esteban Yan | 803 | 815 | -12 |
| 2004-09-29 | vs CHA | 157 | L 2-11 | 70-87 | 4 | 8,944 | Jason Johnson | Freddy Garcia | Freddy Garcia | Jason Johnson | | 805 | 826 | -21 |
| 2004-09-30 | @ TBA | 158 | W 8-0 | 71-88 | 4 | 0 | Jeremy Bonderman | Dewon Brazelton | Jeremy Bonderman | Dewon Brazelton | | 813 | 826 | -13 |
| 2004-09-30 | @ TBA | 159 | L 4-6 | 71-88 | 4 | 10,309 | Wil Ledezma | Mark Hendrickson | Travis Harper | Craig Dingman | Danys Baez | 817 | 832 | -15 |
| 2004-10-01 | vs TBA | 160 | L 1-4 | 71-89 | 4 | 20,612 | Mike Maroth | Rob Bell | Rob Bell | Mike Maroth | | 818 | 836 | -18 |
| 2004-10-02 | vs TBA | 161 | W 5-1 | 72-89 | 4 | 20,029 | Gary Knotts | Scott Kazmir | Gary Knotts | Scott Kazmir | | 823 | 837 | -14 |
| 2004-10-03 | vs TBA | 162 | L 4-7 | 72-90 | 4 | 22,471 | Nate Robertson | John Halama | John Halama | Nate Robertson | | 827 | 844 | -17 |