Reliever Michael Kohn is scheduled to undergo ligament-replacement surgery on his right elbow Thursday and will miss the 2012 season, the Angels announced.
Kohn's star was on the rise at this time last year, but he struggled early and spent the majority of last season at Triple-A Salt Lake. He made five appearances this spring, but was placed on the 15-day disabled list when the Angels opened the season.
Tommy John surgery, named after the former Dodgers' left-hander, typically requires a year-and-a-half of recovery time.
Kohn, 25, is 2-1 with a 4.01 ERA in 38 major-league games. Dr. James Andrews will perform the surgery in Florida.