| SP | Burnett, A.Burnett, A.J. >> | 27 | 2004 | R | 93 | 27 | 27 | 12 | 10 | 4.30 | .320 | 1.37 | 9.3 | 3.1 | 6.1 | 175.2 | 181 | 88 | 84 | 22 | 60 | 119 | 0 | 0 | 0 | 0 | 14 | 7 | 3 | 4.42 |
| SP | Greinke, Z.Greinke, Zack # >> | 21 | 2004 | R | 76 | 26 | 26 | 10 | 4 | 3.87 | .278 | 1.14 | 7.9 | 2.4 | 6.1 | 174.1 | 153 | 79 | 75 | 13 | 46 | 117 | 0 | 0 | 0 | 0 | 16 | 2 | 3 | 3.45 |
| SP | Lopez, R.Lopez, Rodrigo >> | 29 | 2004 | R | 65 | 26 | 26 | 2 | 9 | 4.86 | .336 | 1.47 | 9.9 | 3.4 | 6.1 | 107.1 | 118 | 59 | 58 | 15 | 40 | 72 | 0 | 0 | 0 | 0 | 0 | 5 | 8 | 4.74 |
| SP | Williams, W.Williams, Woody # >> | 38 | 2004 | R | 44 | 26 | 26 | 7 | 11 | 5.38 | .347 | 1.55 | 10.2 | 3.7 | 6.3 | 159.0 | 181 | 95 | 95 | 19 | 66 | 112 | 0 | 0 | 0 | 0 | 11 | 7 | 4 | 4.52 |
| SP | Mulder, M.Mulder, Mark >> | 27 | 2004 | L | 38 | 26 | 26 | 5 | 6 | 6.08 | .363 | 1.67 | 10.5 | 4.5 | 6.6 | 142.0 | 166 | 101 | 96 | 23 | 71 | 104 | 0 | 0 | 0 | 0 | 8 | 6 | 8 | 5.27 |
| RP | Rincon, J.Rincon, Juan >> | 25 | 2004 | R | 94 | 68 | 0 | 7 | 4 | 3.15 | .294 | 1.22 | 7.0 | 4.0 | 9.4 | 91.1 | 71 | 35 | 32 | 9 | 40 | 95 | 0 | 2 | 3 | 0 | 0 | 3 | 3 | 3.62 |
| RP | Alvarez, W.Alvarez, Wilson † >> | 34 | 2004 | L | 66 | 61 | 0 | 13 | 5 | 3.83 | .309 | 1.30 | 8.3 | 3.4 | 6.0 | 136.1 | 125 | 59 | 58 | 17 | 52 | 90 | 0 | 18 | 9 | 0 | 0 | 6 | 3 | 4.58 |
| RP | Leicester, J.Leicester, Jon >> | 25 | 2004 | R | 27 | 34 | 0 | 2 | 1 | 3.33 | .258 | 1.00 | 6.3 | 2.7 | 6.5 | 46.0 | 32 | 17 | 17 | 3 | 14 | 33 | 0 | 0 | 1 | 0 | 0 | 2 | 0 | 3.46 |
| SP | Trachsel, S.Trachsel, Steve >> | 34 | 2004 | R | 26 | 0 | 0 | 0 | 0 | - | .000 | - | - | - | - | 0.0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | - |
| SP | Colon, B.Colon, Bartolo >> | 31 | 2004 | R | 37 | 3 | 0 | 1 | 0 | 3.52 | .425 | 2.09 | 14.1 | 6.4 | 2.6 | 7.2 | 11 | 3 | 3 | 0 | 5 | 2 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 5.00 |
| SP | Garland, J.Garland, Jon >> | 25 | 2004 | R | 28 | 16 | 0 | 1 | 4 | 12.52 | .444 | 2.39 | 16.0 | 5.5 | 5.9 | 23.0 | 41 | 32 | 32 | 6 | 14 | 15 | 0 | 2 | 2 | 0 | 0 | 0 | 1 | 6.91 |