| Most Unearned Runs Allowed | |||||||
|---|---|---|---|---|---|---|---|
| Player | Team | Year | Age | IP | R | ER | UER |
| Matt Weeks | DET | 2012 | 25 | 163.0 | 122 | 98 | 24 |
| Juan Rivera | WAS | 2006 | 30 | 183.1 | 151 | 128 | 23 |
| Adam Guss | LAD | 2017 | 27 | 180.1 | 114 | 92 | 22 |
| Fernando Lipsey | CIN,KC | 2009 | 25 | 180.0 | 106 | 84 | 22 |
| Kory Dearing | TEX | 2018 | 32 | 170.0 | 112 | 90 | 22 |
| Dave Beyke | TOR | 2012 | 28 | 171.0 | 95 | 73 | 22 |
| Bryan Dedmon | MIN | 2030 | 34 | 154.0 | 111 | 89 | 22 |
| Josh Janney | SD | 2012 | 24 | 69.0 | 68 | 47 | 21 |
| Ron Gibney | MIA | 2008 | 28 | 212.2 | 141 | 120 | 21 |
| Joey Thomas | WAS | 2004 | 42 | 221.1 | 108 | 87 | 21 |
| Matt Tarka | HOU | 2027 | 28 | 178.1 | 103 | 82 | 21 |
| Chris Diles | PHI | 2030 | 25 | 194.1 | 125 | 104 | 21 |
| Anwell Kea | NYM | 2044 | 28 | 159.0 | 104 | 83 | 21 |
| Kyle Peterson | CIN | 2019 | 27 | 153.0 | 106 | 86 | 20 |
| Jaiden Frazier | STL | 2026 | 28 | 153.0 | 109 | 89 | 20 |
| Trent Downey | MIA | 2024 | 28 | 153.2 | 101 | 81 | 20 |
| Newton Smith-Stanley | SF | 2038 | 31 | 192.2 | 90 | 70 | 20 |
| Terry Burke | DET | 2039 | 24 | 191.0 | 95 | 75 | 20 |
| Cassidy Fine | VA | 2046 | 31 | 188.0 | 102 | 82 | 20 |
| Mike Vacchiano | CHC | 2018 | 27 | 156.0 | 94 | 75 | 19 |