Murray missed part of practice Wednesday and underwent an MRI on his hamstring. He missed all of practice Thursday. Coach Chip Kelly said he would be evaluated after Friday and Saturday practices.
"He'll be fine," the source told ESPN. "He'll play."
Murray, the NFL's rushing leader last season with 1,845 yards, has been held to just 11 yards on 21 attempts this season.
Playing behind a rebuilt offensive line, Murray has been constantly hit behind the line of scrimmage. He was visibly upset during last week's game against the Dallas Cowboys -- his former team -- in which he gained only 2 yards on 13 carries.
Ashley Fox covers the NFL for ESPN.