Stephenson out until after All-Star break

Cardinals right-hander Garrett Stephenson underwent surgery to repair and remove a damaged muscle in his left hamstring Thursday, and doctors don't expect him to return until after the All-Star break.

St. Louis placed Stephenson on the 15-day disabled list Tuesday, after he aggravated his sore left hamstring during a bullpen throwing session a few days earlier.

In his last appearance May 29, Stephenson worked a season-low 2 1/3 innings against Houston, giving up six runs and six hits with three walks. Stephenson also has missed time this season because of back spasms.

Stephenson is 1-4 with a 6.67 ERA in seven starts. He won 16 games in 2000 but missed last season because of reconstructive elbow surgery.