DENVER — Colorado setup man Taylor Buchholz will have season-ending Tommy John surgery on his right elbow.

The right-hander, who has been on the disabled list all season, will have the surgery this week.

Buchholz sprained the ligament while warming up in the bullpen before his first spring training appearance on Feb. 26 against the Chicago White Sox.

An MRI revealed a partially torn ligament, but not torn enough where the medical staff felt he needed surgery. Instead, they chose a rehab schedule that would allow him to come back without doing surgery. That ended with a bullpen session Saturday when four pitches into it he began to experience discomfort in the same area. He threw 17 more pitches and the session was shut down.