Mets RH reliever Anthony Swarzak has been diagnosed with a strained left calf and will receive treatment on Thursday, the team announced.
Swarzak left Tuesday's game against the Astros in the top of the third inning due to the injury.
He ran to cover first base on a grounder to first baseman Adrian Gonzalez, but was unable to catch what was an on-target toss from Gonzalez that would have ended the inning.
Swarzak, whose injury was confirmed Wednesday after an MRI, said he felt something "grab" while running to cover first base.
"I'm walking," he said after departing the game. "I'm standing here right now, so I think we're going to be OK."