Mets Place Matt Harvey On 15-Day DL

5:07pm: Harvey is seeing Dr. Thompson to check out the team’s “suspicion” that Harvey could be dealing with thoracic outlet syndrome, Newsday’s David Lennon tweets. The syndrome involves a compression of nerves and/or blood vessels in the shoulder area, and can be quite painful.

Several hurlers have dealt with it in recent years; most recently, Phil Hughes underwent season-ending surgery to treat his own bout with the issue. In his case, though, he had been pitching through it for quite some time. Royals righty Chris Young also had work done to alleviate his issues, which gave his career new life. Beyond the Box Score’s Nick Lampe took an interesting look at pitchers who have undergone surgery to address thoracic outlet syndrome, with mixed results.

4:35pm: The Mets have placed righty Matt Harvey on the 15-day DL, per a club announcement. The teams says that Harvey is dealing with right shoulder discomfort.

This news raises yet more serious concerns about a pitcher who already hasn’t looked himself this year. Expected to lead a rotation full of outstanding arms, Harvey has instead been the black sheep of the group, pitching to a 4.86 ERA with 7.4 K/9 and 2.4 BB/9 over 92 2/3 innings. There have been some ups and downs mixed in, but the aggregate falls shy of the ace-level results that Harvey has traditionally posted.

It’s not immediately clear whether this is a long-simmering issue or a newly-arising problem, but a glance at Harvey’s Brooks Baseball page shows one apparent change in recent weeks: a sudden and drastic shift in his horizontal arm slot. He’ll visit shoulder specialist Dr. Robert Thompson, who — as Marc Carig of Newsday notes on Twitter — is an expert in vascular issues such as thoracic outlet syndrome.

Harvey had returned from Tommy John surgery last year in dramatic fashion, logging 189 1/3 innings of 2.71 ERA ball with 8.9 K/9 and 1.8 BB/9. That was a largely unprecedented jump in innings for a pitcher who was working with a new UCL, and Harvey went on to throw another 26 2/3 in the post-season — which also shortened his winter rest period. While we haven’t heard of any elbow-related concerns, it’s hard not to wonder whether there could be any connection between that series of events and Harvey’s current malady.

New York has called up righty Seth Lugo to take Harvey’s place on the active roster, but he’s not an option to step into the rotation. For the time being, the club will likely go to swingman Logan Verrett, as they have on several prior occasions this year.

[Related: Updated Mets Depth Chart]

In the event that Harvey requires a lengthier absence, things could begin to get tricky. Steven Matz is pitching through a painful bone spur at the moment, so he’s a bit of a question mark, too. And the obvious replacement – Tommy John rehabber Zack Wheeler — is still not throwing bullpen sessions, per another Carig tweet. That’s still an enviable pitching situation, but a piece or two of bad luck could raise some real depth concerns with the cub’s key area of strength.

That’s not to say that there aren’t other pieces on hand. Former top prospect Rafael Montero is still pitching at Triple-A, but the results haven’t been pretty. Also working in Las Vegas are hurlers such as Gabriel Ynoa and Sean Gilmartin. Ynoa may be at the top of the team’s list among its farmhands, Mike Puma of the New York Post suggests on Twitter.