"It can heal by itself. If there is any room for optimism, that would be it. He will be reevaluated in two weeks."
The loss of Niese, the Mets' Opening Day starter, puts the team back into a five-man rotation that manager Terry Collins had hoped to stretch to six to give his starters an extra day of rest through the middle portion of the season. With prized young arms like Matt Harvey and Zack Wheeler, Collins' discretion seemed the better part of valor, but despite two encouraging efforts by veteran Carlos Torres since his callup from Triple-A Las Vegas, he will remain the long man unless another pitcher goes down.
"Jon Niese was our No. 1 guy coming out of Spring Training," said Collins. "This does not help us.
"This tells you that you cannot have enough starting pitching. We lost Johan Santana, we were lucky to have Jeremy Hefner. And now we have lost Jon Niese, we are very lucky that Carlos Torres has gotten off to the start he has. Now, he protects us.
Wheeler will assume Niese's spot in the rotation.
"We are very lucky to have a Zack Wheeler in our organization," Collins said. "And we have some more coming if Dillon Gee's elbow flares up again or somebody takes a ball off the kneecap."
Though Niese missed a start in early June with shoulder tendinitis, the Mets said that Thursday night's problems came without warning.
"I talked to Jon after the game, and he said it was just during that one at-bat that he felt it getting sorer and sorer," said Collins.
The Mets filled Niese's roster spot by recalling right-hander Greg Burke for his third stint with the team in 2013.
Jay Greenberg is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.