Mets righty Robert Gsellman to have surgery on left shoulder

It wouldn’t be the offseason if Mets players weren’t having surgery

Mets right-hander Robert Gsellman will have surgery Wednesday to repair a partially-torn labrum in his left shoulder, reports Adam Rubin of ESPN.

After everyone started wondering in September why Gsellman wouldn’t swing while at the plate, it was reported that he couldn’t swing.

He had been dealing with the labrum tear since he was with Triple-A Las Vegas earlier this season.

Fortunately for the Mets and Gsellman, the injury is to his non-throwing shoulder. And the surgery will be arthroscopic.

So while Gsellman will be on the mend for a bit, he should be ready well in advance of Spring Training in February.

Along with Seth Lugo, Gsellman helped save the Mets’ season after Jacob deGrom and Steven Matz joined Matt Harvey on the sidelines.

Using a fastball that sat around 94 MPH and impressive secondary pitches, Gsellman had a 2.42 ERA (2.63 FIP) and 1.28 WHIP with 15 walks and 42 strikeouts in 44.2 innings (seven starts, one relief appearance).

And when looking at his FIP (2.63), strikeout rate (8.46 per 9), and ground ball rate (Gsellman’s 54.2 percent), it doesn’t seem like his traditional numbers were a fluke.

It wouldn’t be rational to expect Gsellman to pitch to a 2.42 ERA from here on out, but his stuff plays. And his mound presence was terrific.

Without factoring in Zack Wheeler, if the Mets bring back Bartolo Colon and their three starting pitchers coming off surgery — Matt Harvey, Jacob deGrom, Steven Matz — are good to go, there won’t be room for Gsellman in the starting rotation in 2017.

If the above happens, and as much as pitching in Triple-A Las Vegas can be miserable, that’s probably where Gsellman would end up to start next season.

It would be tempting to use Gsellman in the big league bullpen. But it makes more sense to keep him stretched out as a starting pitcher.