Matz was moved to the bullpen and felt discomfort in a relief appearance on Saturday.

Matz is 0-4 with an 8.63 ERA in six appearances and Saturday was his first time in relief this season. He allowed four combined runs in his first two starts, but was tagged for 19 runs in his next three starts and pulled from the rotation after allowing six runs in a 6-2 loss at Philadelphia on Aug. 15.

Matz made his debut for the Mets in 2015, but he has spent time on the injured list in every season.

He missed nearly two months as a rookie with a lat injury, missed the final month of 2016 with left shoulder tightness and had two stints on the injured list in 2017 with left elbow injuries.

Matz briefly was sidelined in the previous two seasons and Sunday said the injury was a surprise because of how well he had been feeling.

“I was feeling so good coming in,” Matz said. “My arm was feeling really strong and healthy, so I’m pretty bummed about it.”

To replace Matz and Betances on the active roster, the Mets recalled right-handed relievers Drew Smith and Franklyn Kilome from the alternate site in Brooklyn.

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