McMahon is out of Friday's lineup against the Diamondbacks.
The Rockies have started the season against back-to-back lefties, so McMahon has yet to start a game this season. Ian Desmond will once again slot in at first base and hit sixth against lefty Robbie Ray. McMahon appeared as a pinch hitter Thursday and went 0-for-1 with a strikeout. Look for him to be in the lineup Saturday against righty Zack Greinke.