Murphy will miss 4-to-6 weeks with a hairline fracture of his right forearm, MLB.com's Thomas Harding reports.
He was hit by Anthony Rizzo's bat during the first inning of Saturday's game, yet remained in, so this news comes as a shock. Murphy's injury wasn't healing, so he went for tests this week that discovered the fracture. He should open the year on the disabled list; as such, Dustin Garneau figures to break camp on the active roster, spelling Tony Wolters against southpaws until Murphy is ready to return.