Grichuk informed the trainers of the discomfort as the Cardinals were batting in the bottom of the sixth. After the inning ended, Matheny was summoned over, and at that point he decided to send Peter Bourjos out to center field in Grichuk's place.
"We catch something early, it could save him significant time," Matheny said afterward. "We're going to get doctors to take a look at it and then evaluate and see where we are."
Grichuk was not available for comment postgame to specify when the injury occurred. A Cardinals spokesperson, relaying information from the team's medical staff, said Grichuk felt the pull while running the bases. Grichuk singled in the fourth and advanced to third on another single and groundout. He grounded out in the fifth, which was his final at-bat of the afternoon.
Grichuk has been a starting outfielder for the Cardinals basically since returning from the disabled list on May 16. Prior to that, he missed 27 games due to a back injury.
In the 62 games he's played since rejoining the club, Grichuk has hit .285/.339/.556 with 32 runs, 16 doubles, six triples, 10 homers and 34 RBIs.
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, follow her on Twitter @LangoschMLB, like her Facebook page Jenifer Langosch for Cardinals.com and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.