Murphy's arm struck the bat of the Cubs' Anthony Rizzo while he was trying to throw to second on a steal attempt Saturday. The ball sailed into center field and Rizzo was called for interference. Murphy stayed in the game until the seventh, as planned. His injury wasn't discovered until later.
He is in a splint but won't need surgery, manager Bud Black said.
The injury comes on the heels of the team learning that first baseman Ian Desmond will undergo surgery after being hit on the hand by a pitch. Rockies general manager Jeff Bridich told ESPN's Jim Bowden that Desmond will miss approximately six weeks.
Also, right-hander Chad Bettis is undergoing chemotherapy and is out indefinitely after discovering a recurrence of his testicular cancer during a routine follow-up. Other spring training injuries include left-hander Chris Rusin (oblique) and outfielder David Dahl (ribs).
Murphy had a .266 average in 32 games over the past two seasons with eight home runs and 22 RBIs. With Murphy out, the Rockies will turn to Tony Wolters and Dustin Garneau at catcher, although Black said he'd consider other options.