Murphy was optioned to Triple-A Worcester on Monday.
Murphy covered four innings out of the bullpen in Sunday's loss to the Dodgers, and with that kind of workload presumably making him unavailable for at least a couple days, the Red Sox decided to remove him from the roster and replace him with fellow reliever Kyle Barraclough, who was called up from Triple-A. Now that he's back with Worcester, Murphy should slide back into the rotation.