| SP | Schilling, C.Schilling, Curt >> | 37 | 2003 | R | 98 | 24 | 24 | 6 | 10 | 5.74 | .341 | 1.53 | 10.7 | 3.1 | 8.5 | 147.1 | 175 | 96 | 94 | 35 | 50 | 139 | 2 | 0 | 0 | 1 | 11 | 4 | 3 | 5.31 |
| SP | Oswalt, R.Oswalt, Roy # >> | 26 | 2003 | R | 84 | 23 | 23 | 11 | 7 | 4.06 | .293 | 1.22 | 8.6 | 2.3 | 6.4 | 153.0 | 147 | 71 | 69 | 23 | 39 | 109 | 2 | 0 | 0 | 0 | 13 | 4 | 1 | 4.37 |
| SP | Clemens, R.Clemens, Roger >> | 41 | 2003 | R | 78 | 22 | 22 | 9 | 9 | 4.72 | .305 | 1.28 | 9.1 | 2.5 | 7.3 | 145.0 | 146 | 78 | 76 | 20 | 40 | 117 | 1 | 0 | 0 | 0 | 10 | 5 | 4 | 4.11 |
| SP | Miller, W.Miller, Wade >> | 27 | 2003 | R | 58 | 22 | 21 | 8 | 7 | 4.86 | .316 | 1.37 | 8.6 | 3.8 | 6.4 | 120.1 | 114 | 65 | 65 | 16 | 51 | 85 | 0 | 0 | 0 | 0 | 7 | 2 | 1 | 4.64 |
| RP | Mantei, M.Mantei, Matt # >> | 30 | 2003 | R | 92 | 75 | 0 | 2 | 5 | 7.10 | .328 | 1.44 | 8.5 | 4.5 | 9.7 | 52.0 | 49 | 42 | 41 | 8 | 26 | 56 | 0 | 6 | 2 | 0 | 0 | 1 | 1 | 4.40 |
| RP | Guardado, E.Guardado, Eddie >> | 33 | 2003 | L | 87 | 77 | 0 | 3 | 0 | 3.31 | .242 | 0.92 | 5.9 | 2.4 | 8.3 | 49.0 | 32 | 19 | 18 | 2 | 13 | 45 | 0 | 3 | 0 | 0 | 0 | 2 | 3 | 2.61 |
| RP | Calero, K.Calero, Kiko >> | 28 | 2003 | R | 65 | 28 | 0 | 0 | 1 | 3.16 | .319 | 1.32 | 6.1 | 6.1 | 9.7 | 25.2 | 17 | 9 | 9 | 3 | 17 | 27 | 0 | 3 | 1 | 0 | 0 | 2 | 0 | 4.68 |
| SP | Wakefield, T.Wakefield, Tim >> | 37 | 2003 | R | 47 | 16 | 1 | 1 | 2 | 4.96 | .313 | 1.37 | 9.2 | 3.1 | 7.9 | 49.0 | 50 | 27 | 27 | 7 | 17 | 43 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 4.14 |