"He said when he was loosening up, he felt it a little bit, thought it was nothing he couldn't pitch through," said Collins. "When the game was over, it bothered him pretty good. We had him looked at here and they decided to send him to New York."
Collins said Matsuzaka would have an MRI on Friday and the team would make a decision from there. The Mets had only six in the bullpen on Friday, and Collins said the team would call up another pitcher for Saturday's game if Matsuzaka's results made it necessary.
Matsuzaka was bumped to the bullpen on July 20 after a month and a half of being mainly a starter. He carried a 2-3 record and 4.24 ERA as a starter but has had more success in relief, striking out more than 10 batters per nine innings and holding a 3.25 ERA.
Caitlin Swieca is an associate reporter for MLB.com. Follow her on Twitter at @CaitlinSwieca. This story was not subject to the approval of Major League Baseball or its clubs. This story was not subject to the approval of Major League Baseball or its clubs.