Sean SullivanCOL · SP

2026 review

Sean Sullivan was a rookie righty who couldn't miss bats or find the strike zone in a short big-league look for COL. He went 0-3 with an 8.87 ERA and a 2.01 WHIP in 22.1 IP over 5 starts, with a 14.0 K% and a 9.6 BB% over 114 BF, allowing 5 HR along the way. COL selected his contract Jun 12, optioned him Jun 30, recalled him Jul 4, then placed him on the 15-day IL Aug 3 retroactive to Jul 5; he took a rehab assignment Sep 10 before being optioned again Sep 16, missing 84 regular-season days on that stint. Undrafted in NFBC drafts, he finished 1201st of 1472 in the TDK LABS 5x5 value rank, 757th of 811 pitchers and 199th of 236 starting pitchers. His 8.87 ERA ran 4.05 above his 4.82 xERA over 114 BF. His 14.0 K% over 114 BF was the 21st lowest of 517 pitchers with 100+ BF, and his 7.3 SwStr% over 412 pitches was also the 21st lowest of 517 pitchers with 100+ BF. By mid-Jun the TDK LABS card had him getting promoted for his debut; by late Jun it read as a rough debut in Coors, and by mid-Jul it had him optioned after a difficult outing and then sidelined for an extended stretch.