The right-hander came up lame after legging out a triple and was replaced by pinch-runner Corey Dickerson on the bases. Wilton Lopez replaced Chatwood on the mound to start the bottom of the frame.
"It doesn't seem like it was too bad," Rockies manager Walt Weiss said. "Hopefully, it was just a cramp. We'll know more in the morning."
"I told him to take one pitch and hit a double so when I went out there I told him, 'I told you to hit a double, not a triple,'" Weiss said. "He said, 'I know. I messed it up.'"
Chatwood struck out one batter and walked one in two scoreless innings before the injury. He went 8-5 with a 3.15 ERA in 20 starts for the Rockies last season.
Jesse Sanchez is a national reporter for MLB.com. Follow him on Twitter @JesseSanchezMLB. This story was not subject to the approval of Major League Baseball or its clubs.