Manager Torey Lovullo said Greinke exited Wednesday's game against the Pirates with abdominal tightness, Zach Buchanan of The Athletic reports.
Greinke apparently suffered the injury on his final pitch of the day. The right-hander will undergo an MRI on Friday, after which the severity of the injury should clear up. Prior to exiting with the injury, Greinke had allowed just five baserunners (four hits, one walk) while striking out five across 7.2 scoreless innings.