Cleveland Indians starter Mike Clevinger will miss at least six weeks with a back muscle injury.

The Indians placed the right-hander on the 10-day injured list retroactive to Monday. He was pulled from Sunday’s 3-1 victory against Toronto after five innings and 75 pitches.

The team announced Tuesday that Clevinger has strained his teres major, a muscle in his upper back. Manager Terry Francona said it would be six to eight weeks before he picks up a ball and resumes pitching activity.

Clevinger is 1-0 and has not allowed an earned run in 12 innings over two starts this season, striking out 22. The 28-year-old was 13-8 with a 3.02 ERA last season.

The Indians called up righty Nick Wittgren, a reliever from Triple-A Columbus. The 27-year-old Wittgren was acquired in a trade with Miami on Feb. 4 and made eight relief appearances this spring with Cleveland, posting a 3.86 ERA.