PORT ST. LUCIE, Fla. - Mets lefthander Jonathon Niese, who had been in line to make his second consecutive Opening Day start, has been sent back to New York to undergo an MRI exam on his bothersome throwing shoulder.
Niese missed nearly two months last year with a partially torn rotator cuff in his left shoulder, although manager Terry Collins said Niese's latest bout with discomfort is closer to the triceps area.
"It's precaution right now," Collins said Wednesday. "But any time you send somebody for an MRI, obviously there's going to be a concern until you get the reading back."
Niese played down the severity of his injury.
"Last year, when there was pain, it was difficult to do everyday things such as turn a steering wheel or put on a belt," Niese told MLB.com. "There's no pain with any of that now, so I don't foresee it being serious at all."
Niese, 27, finished 8-8 with a 3.71 ERA in 24 starts. He is entering the third season of a five-year, $25.5-million deal. With Matt Harvey expected to miss most, if not all of the season recovering from Tommy John surgery, Niese had been expected to anchor the starting rotation.
Collins said Niese complained of discomfort after throwing a side session early in camp. He briefly had been kept from throwing off a mound and allowed only to long toss.
Niese eventually returned to the mound and even threw live batting practice this week along with the rest of the team's pitchers. But after a recent session, he felt fatigue in his left shoulder.
Collins said Niese likened the sensation to having a dead arm.
"In the second 20 pitches, he said his arm just felt kind of like it was a lot of work," Collins said.
The Mets don't open Grapefruit League play until Friday against the Nationals, which follows Thursday's scheduled intrasquad game. Nevertheless, the Mets already have dealt with some injuries.
Collins said Bartolo Colon, another member of the starting rotation, was held out from some of Wednesday's workouts with tightness in his calf. Colon, 40, spent part of the day receiving treatment from trainers. Throughout camp, he has regularly been excused from certain running drills.
Meanwhile, outfielder Eric Young Jr. complained of tightness in his side, although he is still scheduled to play in exhibition games beginning this weekend.