| Most Unearned Runs Allowed | |||||||
|---|---|---|---|---|---|---|---|
| Player | Team | Year | Age | IP | R | ER | UER |
| Tom Bow | ATL | 2027 | 25 | 160.0 | 132 | 105 | 27 |
| Howell Hepburn | MIL | 2022 | 27 | 221.2 | 126 | 100 | 26 |
| Justin Bracken | NY | 2027 | 24 | 232.0 | 115 | 89 | 26 |
| Adam Smallwood | OHI | 2025 | 25 | 174.1 | 132 | 107 | 25 |
| John Lahoda | ATL | 2028 | 28 | 209.0 | 134 | 112 | 22 |
| Bret Gilbert | CHI | 2018 | 29 | 159.2 | 119 | 98 | 21 |
| Jonathan Astorga | CHI | 2028 | 27 | 241.1 | 126 | 105 | 21 |
| Lane Navarro | CHI | 2028 | 29 | 201.0 | 147 | 127 | 20 |
| Alex Rivera | CHI | 2026 | 25 | 201.2 | 115 | 95 | 20 |
| Andy Boyles | WAS | 2021 | 31 | 223.2 | 150 | 131 | 19 |
| Layton Etter | HOU | 2024 | 29 | 140.0 | 162 | 143 | 19 |
| Isaiah Strachan | ATL | 2026 | 28 | 200.1 | 137 | 118 | 19 |
| Roger Damian | CGY | 2028 | 28 | 195.1 | 120 | 101 | 19 |
| Roberto Gonzalez | DET | 2028 | 28 | 224.1 | 141 | 122 | 19 |
| Dusty Hertz | SEA | 2025 | 33 | 195.0 | 158 | 140 | 18 |
| Andrew Ward | BOS | 2021 | 33 | 120.1 | 57 | 39 | 18 |
| Willie Salazar | WAS | 2025 | 33 | 210.0 | 123 | 105 | 18 |
| Layton Etter | HOU | 2025 | 30 | 147.0 | 124 | 106 | 18 |
| Mario Morales | HOU | 2023 | 39 | 161.1 | 109 | 91 | 18 |
| Al Wooldridge | BOS | 2019 | 24 | 198.2 | 107 | 89 | 18 |