"There's no question," manager Terry Collins said. "When it bothers you on a night where it's nice and warm, it's a little concerning. I'm a little concerned, yeah."
Grimacing as he delivered his 61st pitch of the night, a changeup to Tyler Pastornicky with one out in the fourth and the Mets trailing, 3-2, Niese left the game following a brief mound conference with Collins, pitching coach Dan Warthen and trainer Ray Ramirez. A Braves team doctor performed preliminary tests on Niese, all of which came up negative. But the Mets will know more following Friday's more thorough examination, which should include an MRI.
Though he did not feel any pain until the Pastornicky at-bat, Niese said his discomfort during that sequence, combined with a noticeable loss in velocity, caused him to call out the training staff.
"It just felt really weak," Niese said of his shoulder.
Niese, 26, skipped a start earlier this month with left shoulder tendinitis, but said recently that he felt the problem was behind him. As recently as Thursday afternoon, Collins affirmed that health was no longer an issue for Niese, whose lengthy injury history never included arm trouble until this year.
"I took off a start last time and I felt great after that," Niese said. "We'll see what the doctors say."
By giving up three runs on eight hits in 3 1/3 innings, Niese raised his ERA to 4.32 ERA on the year. Though he has consistently downplayed the severity of his shoulder issues, Niese has clearly not been the same pitcher as he was last season, when he set career bests in innings, strikeouts, wins and ERA.
Pitching with a slightly lower average velocity than in years past, Niese has seen his strikeout rate plummet while his walk rate has nearly doubled. As a result, his ERA has spiked.
Injuries may be nothing new to Niese, who never enjoyed a full, healthy season until last year. But trouble tended to steer clear of his left arm; Niese missed time with hamstring injuries and oblique woes, but never a major shoulder or elbow strain.
After undergoing a rhinoplasty reconstruction two winters ago, Niese boasted that he was able to improve his cardiovascular conditioning in an attempt to stay healthy. And it worked -- he responded with the best season of his young career, his first since signing a five-year, $25.5 million contract with enough options to keep him under team control through 2018.
As a result, the Mets named Niese their Opening Day starter this spring, often mentioning him in the same breath with Harvey and Wheeler. Though Niese may not boast the same frontline talent as those two, he is every bit the rotation cog.
"He kind of slides right into that plan that everybody talks about," third baseman David Wright said. "You talk about the electric stuff of both Harvey and Wheeler, but then Niese I think is a front-end type guy that if he's healthy and he's right -- I still think whether it's injuries or just inconsistencies, he's very, very underrated. When he's on, he's as tough as anybody from the left side."