- Full name Aaron James Bummer
- Born 09/21/1993 in Valencia, CA
- Profile Ht.: 6'3" / Wt.: 215 / Bats: L / Throws: L
- School Nebraska
- Debut 07/27/2017
- Drafted in the 19th round (558th overall) by the Chicago White Sox in 2014 (signed for $100,000).
Organization Prospect Rankings
Bummer was a three-year contributor at Nebraska who earned a weekend rotation role as a junior. He pitched to a 3.34 ERA that season, though he struck out fewer than six batters per nine innings. Still, the White Sox selected him in the 19th round of the 2014 draft and shifted him to the bullpen. Bummer succeeded right away by punching out 28 batters in 22 innings at Rookie-level Great Falls in his debut. He missed the entire 2015 season, however, after having Tommy John surgery. He returned to the mound in mid-2016 and quickly and emphatically established himself as a prospect by jumping to high Class A Winston-Salem. Bummer lacked consistency, as do many pitchers recovering from Tommy John surgery, but showed a fastball that grades as at least plus. He reached 99 mph at his best and sat 91-96 on his worst days. Bummer's slurvy breaking ball has been clocked in the upper 80s, giving him a second plus pitch. He is on track to start 2017 at Double-A Birmingham.