Jayson Werth left in ninth inning of Saturday's 10-9 loss to the St. Louis Cardinals with cramping in his hamstring. Nationals Manager Davey Johnson pulled Werth to start the inning, moved Bryce Harper to right field and Eury Perez made his major league debut by taking over center field. Werth said the cramping wasn't expected to be a serious issue.

Werth has been the Nationals hottest hitter and an on-base machine since his return from a broken wrist on Aug. 2. He is hitting .350 (35 for 100) and scoring 20 runs over the past 27 games. He started in right field and smacked a double and scored a run in Saturday's game.