Colorado Rickies pitcher Jhoulys Chacin, who is 3-0 with a 1.46 ERA this season, was placed on the 15-day disabled list with a lower back strain, the Denver Post reported.
Chacin suffered the injury in the seventh inning of Friday's game.
The Rockies are hoping Chacin will miss only two starts.
Tyler Chatwood or Drew Pomeranz is likely to replace Chacin in the rotation while he is out.
Rob Scahill was called up from Triple-A Colorado Springs to take Chacin's spot on the roster, but he is scheduled to pitch in relief.