PHILADELPHIA -- New York Mets pitcher Taijuan Walker left his start Monday night against Philadelphia after two innings because of right shoulder irritation.
He will undergo an MRI on Tuesday.
Walker struck out four, walked none and threw 30 pitches, retiring all six batters before he left the game. David Peterson started the third inning.
The Mets went on to blow a four-run lead to fall 5-4 to the Phillies.
Walker went 7-11 with a 4.47 ERA last season, his first with the Mets.
The Associated Press contributed to this report.