Philadelphia Phillies slugger Bryce Harper exited Sunday's 6-3 loss to the Toronto Blue Jays with lower back stiffness after he struck out with the bases loaded in the seventh inning.

Harper took a slow walk in the dugout toward the clubhouse and signaled to manager Joe Girardi he was done for the day.

Girardi said Harper will get treatment and that Harper's status for Monday's game is unknown.

Harper has 11 homers and 28 RBIs for the Phillies, who are trying to hang on over the final week and secure their first playoff berth since 2011.

The Associated Press contributed to this report.