The St. Louis Cardinals have the best record in the National League, but one of their key players, outfielder Matt Holliday, had to leave Thursday's game with tightness in his right hamstring.
Holliday was injured while running out on a ground out in the fourth inning.
It's unclear how severe the injury is.
"I've been icing in and getting treatment and I'll get a better feel of what it looks like tomorrow," he said. "Hopefully it will be day-to-day."
Holliday is hitting .268 with 13 home runs this season.