Sean Manaea (forearm) will undergo an MRI on Tuesday.
Manaea exited Monday's start against the Rangers with a strain to the pronator muscle in his left forearm. The rookie southpaw said that his forearm has bothered him on a couple of occasions this season, but that he was able to pitch through them. He wasn't able to on Monday. "I kind of felt it in the fourth inning, warming up," said Manaea. "It kind of loosened up during the inning and then the fifth inning came around and the same thing happened. It was just kind of tight. It just never got loose." More should be known by the middle of the week.