ANAHEIM, Calif. — Los Angeles Angels left-hander Andrew Heaney will have Tommy John surgery, likely sidelining him until the 2018 season.

The Angels announced the decision Thursday in another blow to their injury-plagued lineup.

Heaney entered this season as the No. 2 starter after his promising debut with the Angels, who acquired him in a trade in December 2014. He went 6-4 with a 3.49 ERA in 18 starts last season, and was named the AL's rookie of the month in July.

But Heaney made just one start in April before tearing his ulnar collateral ligament. Heaney hoped to avoid surgery with rest and stem cell therapy, but his elbow wasn't progressing.

Dr. Neal ElAttrache will perform elbow ligament replacement surgery on Heaney on Friday in Los Angeles.