Moyer got Jeff Keppinger to fly out to Shane Victorino on the warning track in center field. But the 46-year-old Moyer appeared to stumble after his follow through, and he landed rather awkwardly.
Moyer put his arm around catcher Paul Bako for some assistance to the dugout.
Moyer relieved J.A. Happ in the sixth inning and recorded four outs before the Phillies went on to win 7-4.
The Phillies announced that Moyer suffered a left groin strain. Moyer did not meet with reporters after the game and his status for Wednesday's game is unknown.
Andy Jasner is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.