Angels' top starter Garrett Richards needs Tommy John surgery

Los Angeles Angels right-hander Garrett Richards has a torn ulnar collateral ligament in his throwing elbow is expected to have season-ending Tommy John surgery, Yahoo Sports first reported Friday.

Richards, 27, is 1-3 with a 2.34 ERA and 34 strikeouts in six starts (34 2/3 innings) this season. He set career highs in wins (15), strikeouts (176) and innings pitched (207 1/3) in 2015.

On Thursday, the Angels announced Richards would miss his scheduled start Friday because of dehydration and fatigue. But the problem turned out to be much more severe.

His loss is a big blow to the Angels, whose rotation ranks 17th in the majors with a 4.45 ERA. Los Angeles is 13-15 and four games behind the AL West-leading Seattle Mariners.

In six major-league seasons, Richards is 40-32 with a 3.58 ERA.