Niese had been dealing with what was labeled shoulder tendinitis (per Adam Rubin), but with Thursday night's events, it has become clear that it could be more than just the tendinitis. Mets manager Terry Collins even told the media earlier in the day that Niese's shoulder was fine, reports Mark Carig of Newday.
The Mets recently went to a six-man rotation, but the injury to Niese will likely bring an end to that experiment. Shaun Marcum would have likely been the odd man out if they went back to five men, so he could stand to benefit from the injury.
Marcum has an ERA of 5.76 in 59 1/3 innings in 2013, but his 53/15 K/BB ratio points to some success for the right-hander moving forward. Niese's injury will at least buy him some time to right the ship.
For the Mets, a season in which they are 27-41 and in fourth place just got a little bit worse, as they could lose their Opening Day starter for a significant period of time.
Niese, 26, has an ERA of 4.15 over 13 starts and 73 2/3 innings pitched in 2013.