Mets pitching coach: Harvey's shoulder 'totally atrophied'

It's been quite a season for the New York Mets, who just can't seem to stay healthy and sit fourth in the National League East with a 39-47 record.

The Mets, who entered the season with what was expected to be one of the game's best rotations, have received just 13 starts thus far from Matt Harvey, with poor results haunting him all season long.

Mets pitching coach Dan Warthen discussed the progress of the "Dark Knight" with Newsday's Marc Carig on Sunday, revealing a shocking piece of news.

Warthen told Carig the procedure Harvey underwent to correct thoracic outlet syndrome in July 2016 led to the problems he's experienced while pitching during the first half of the season.

He said the procedure left weakness in the muscles behind Harvey's throwing shoulder, which has contributed to reduced velocity and the worst season of the 28-year-old's career.

Warthen went on to mention the muscles in Harvey's right shoulder were about half the size of those in his left.

"It totally atrophied," he explained. "He didn’t have the strength to maintain, so his bullpens wouldn’t be good. The first inning would be good and then all of a sudden that thing wouldn’t work, it wouldn’t fire. That’s been the whole thing. We’ve been building that back up the whole time."

After three seasons with an ERA under 2.73 and an All-Star campaign in 2013, Harvey hasn't pitched well in 2016 and '17, allowing 91 earned runs in 163 innings combined, with his walk rate rising (1.8 BB/9 in 2015, 4.5 BB/9 in 2017) and strikeout rate falling (8.9 SO/9 in 2015, 6.9 SO/9 in 2017).