| SP | Crochet, G.Crochet, Garrett BOS † >> | 26 | 2025 | L | 96 | 37 | 37 | 23 | 8 | 2.95 | .269 | 1.09 | 6.7 | 3.2 | 8.4 | 247.0 | 183 | 88 | 81 | 11 | 87 | 230 | 2 | 0 | 0 | 1 | 28 | 2 | 5 | 2.80 |
| SP | Collins, R.Collins, Ray BOS † >> | 23 | 1910 | L | 85 | 36 | 36 | 24 | 3 | 2.85 | .269 | 1.10 | 7.8 | 2.1 | 5.0 | 262.1 | 227 | 98 | 83 | 25 | 62 | 147 | 6 | 0 | 0 | 2 | 28 | 1 | 4 | 3.84 |
| SP | Porcello, R.Porcello, Rick BOS >> | 29 | 2018 | R | 66 | 36 | 36 | 19 | 7 | 3.84 | .301 | 1.26 | 8.8 | 2.6 | 6.6 | 210.2 | 206 | 104 | 90 | 23 | 60 | 154 | 1 | 0 | 0 | 0 | 20 | 6 | 2 | 3.90 |
| SP | Sale, C.Sale, Chris BOS >> | 36 | 2025 | L | 93 | 36 | 36 | 12 | 12 | 4.23 | .294 | 1.25 | 8.2 | 3.0 | 8.6 | 202.1 | 185 | 96 | 95 | 18 | 67 | 193 | 1 | 0 | 0 | 0 | 22 | 1 | 9 | 3.26 |
| SP | Cicotte, E.Cicotte, Eddie BOS >> | 26 | 1910 | R | 61 | 32 | 32 | 10 | 13 | 4.69 | .316 | 1.36 | 8.6 | 3.6 | 3.9 | 188.0 | 180 | 105 | 98 | 23 | 76 | 82 | 3 | 0 | 0 | 2 | 14 | 5 | 5 | 5.01 |
| RP | Chapman, A.Chapman, Aroldis BOS >> | 37 | 2025 | L | 100 | 83 | 0 | 8 | 2 | 2.83 | .254 | 1.01 | 6.3 | 2.8 | 9.6 | 105.0 | 73 | 33 | 33 | 10 | 33 | 112 | 0 | 3 | 4 | 0 | 0 | 1 | 7 | 3.08 |
| RP | Smith, L.Smith, Lee BOS >> | 35 | 1992 | R | 61 | 70 | 0 | 4 | 4 | 3.72 | .267 | 1.08 | 6.5 | 3.2 | 6.5 | 75.0 | 54 | 32 | 31 | 8 | 27 | 54 | 0 | 2 | 4 | 0 | 0 | 1 | 0 | 4.07 |
| RP | Embree, A.Embree, Alan BOS >> | 34 | 2004 | L | 50 | 40 | 0 | 2 | 2 | 4.14 | .311 | 1.33 | 10.8 | 1.3 | 4.4 | 41.1 | 49 | 20 | 19 | 4 | 6 | 20 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 3.80 |
| RP | Schreiber, J.Schreiber, John BOS >> | 31 | 2025 | R | 56 | 36 | 0 | 1 | 1 | 2.45 | .292 | 1.21 | 8.3 | 2.7 | 5.6 | 40.1 | 37 | 18 | 11 | 1 | 12 | 25 | 0 | 0 | 0 | 0 | 0 | 1 | 2 | 3.05 |
| RP | Kimbrel, C.Kimbrel, Craig BOS # >> | 36 | 2024 | R | 50 | 40 | 0 | 1 | 1 | 4.22 | .333 | 1.50 | 7.9 | 5.8 | 9.4 | 42.2 | 37 | 21 | 20 | 2 | 27 | 44 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 3.45 |
| SP | Tudor, J.Tudor, John BOS >> | 34 | 1988 | L | 53 | 28 | 0 | 9 | 5 | 4.72 | .316 | 1.38 | 9.8 | 2.6 | 4.6 | 122.0 | 133 | 65 | 64 | 19 | 35 | 63 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 4.88 |
| CL | Jansen, K.Jansen, Kenley BOS † >> | 37 | 2025 | R | 91 | 71 | 0 | 2 | 4 | 2.14 | .253 | 1.00 | 5.5 | 3.6 | 6.6 | 75.2 | 46 | 20 | 18 | 6 | 30 | 55 | 0 | 45 | 3 | 0 | 0 | 1 | 0 | 3.81 |