"He's been nursing it," manager Ned Yost said. "He's about 80 percent. I just didn't like the way he was running on that play."
Lough figured he pulled something while stealing a base recently.
"I've just been battling it. Hopefully a couple of days and it'll be gone, but it's kind of bothering me a little bit," he said.
The double raised Lough's average to .300 (65-for-217) in 62 games since being recalled from Triple-A Omaha on May 17.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.