Angels' Heaney to undergo Tommy John surgery

Los Angeles Angels starter Andrew Heaney has elected to undergo Tommy John surgery Friday after stem cell injections didn't have the desired effect on his arm.

Heaney was told successful patients are usually asymptomatic after eight weeks and because he wasn't, he elected for surgery.

The Angels' rotation is already depleted, as they're missing Garrett Richards and C.J. Wilson. Richards is out until at least September with a right UCL injury, while Wilson doesn't have a return date as he deals with left shoulder issues.

"Based on the lack of progressive UCL healing in Andrew's case, coupled with the discomfort upon testing the ligament while throwing, we have concluded that Tommy John surgery is the necessary course of action," the club said in a statement Thursday. "Andrew will undergo surgery tomorrow in Los Angeles with Dr. Neal ElAttrache handling the procedure."

Heaney was shut down after his first start April 5, when he gave up four runs on seven hits over six innings against the Chicago Cubs. After the stem cell injections didn't work, Heaney tweeted he opted to forgo the remainder of the season and he isn't sure about a potential return date.

"I don't want to put any timeline on it. I am not going to limit myself," Heaney told MLB.com's Alden Gonzalez. "Those little milestones are going to be little celebrations for me. That's how I'm going to stay positive through it."

Over three big-league seasons, Heaney hasn't seen much major-league time. He's made 26 appearances (24 starts), compiling a 4.09 ERA and a 6-8 record.