Phillies left-hander Cole Hamels underwent an MRI on his left shoulder Monday, according to reports. He experienced tightness in his shoulder during his start against the Nationals on Friday night. Hamels, 13-7 with a 2.62 ERA, is in the midst of his best season, but he allowed three runs and four walks in Friday's loss to Washington. "It's just that part of the year," he said. "It's kind of something when you fatigue a little bit and you have to battle through it and move on to the next game." His next scheduled start is Friday against the Diamondbacks, but Kyle Kendrick will fill in if he can't go.