Angels starter Andrew Heaney to have elbow surgery

Reporting from Boston —  The Angels announced left-hander Andrew Heaney will undergo Tommy John surgery Friday in Los Angeles. The decision was made after his second checkup, Monday, on the progress of a stem-cell injection he received eight weeks ago.

He will miss the remaining half of this season, and, likely, all of 2017.

After his first start of the season on April 5, Heaney told the team he felt tightness in his forearm. After extensive examination, a strained flexor tendon became the diagnosis, and initial instructions were simply to rest.

He resumed throwing not two weeks later. Then, the team shut him down during a trip, saying his rehab had “plateaued.” Heaney said then doctors told him, “‘You can’t get any better trying to throw through it. Let’s go ahead and shut it down and re-evaluate it and make sure that we’re 100% when we start getting back on it.’”

Two weeks later, when it became clear that his ulnar collateral ligament was partially torn, he opted to undergo stem-cell therapy. If it worked, he’d be able to pitch part of this season, and, presumably, next year. He received the injection of his own cells and then waited six weeks until his first checkup, during which an ultrasound suggested the ligament was healing.

The latest examination showed no healing, according to General Manager Billy Eppler, and on Thursday the team decided surgery was “the necessary course of action,” according to a statement.

Dodgers physician Dr. Neal ElAttrache will perform the surgery. Heaney received the stem-cell therapy at the same clinic where Dr. ElAttrache works.

The Angels obtained the 25-year-old Heaney from the Dodgers in December 2014 for second baseman Howie Kendrick. The Dodgers had just acquired him from Miami for second baseman Dee Gordon.

After a rough spring training, Heaney recorded a 3.49 earned-run average over 18 MLB starts last season and opened 2016 as the Angels’ No. 2 starter.

Their ace, Garrett Richards, underwent the same stem-cell treatment two weeks after Heaney, in May. His first checkup indicated healing in his UCL, just as Heaney’s did.

In September, Heaney sold stock in his future earnings, receiving $3.34 million from Fantex in exchange for 10%t of everything he earns as a professional pitcher. He was a 2012 first-round pick by the Marlins out of Oklahoma State.

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Twitter: @pedromoura