July 18 (UPI) -- The New York Mets have placed ace Jacob deGrom on the 10-day injured list because of tightness in his right forearm.
Mets manager Luis Rojas said Saturday that deGrom was day to day after he felt discomfort during a bullpen session Friday in Pittsburgh. He later underwent an MRI that revealed tightness but no structural damage.
The tightness, however, didn't go away Sunday morning, prompting the team to make the move, which is retroactive to Thursday.
Rojas told reporters Sunday that deGrom won't throw again until the forearm discomfort is gone.
"I'm frustrated," deGrom said. "I don't know what else to say. I mean, I guess it probably is good news whenever structurally everything looks good, but you go out there and try to throw a baseball and the forearm just doesn't feel good. The level of frustration right now is very high.
"You want to be out there trying to help your team win baseball games. I think that's where the frustration comes from. And then my job is to run out there every fifth day, and I haven't been able to do that. That's part of the frustration as well, but then you got to get over it and come up with the best plan to get healthy and hopefully stay out there."
The forearm issue is the latest setback for deGrom this season. He missed two weeks with right side tightness in May, then exited his June 11 start due to right flexor tendinitis. He managed to return in time for his next start five days later, but he was forced to depart after three innings with a sore right shoulder.
DeGrom has a 7-2 record and MLB-leading 1.08 ERA over 15 starts this season despite the ailments. He last pitched July 7 against the Milwaukee Brewers.