(Reuters) - Arizona Cardinals running back Ryan Williams will miss the rest of the National Football League season with a shoulder injury that will require surgery, the team said on Monday.
Williams, 22, suffered the injury to his left shoulder on a hard hit during the fourth quarter of Arizona's 17-3 loss to the St. Louis Rams last Thursday and will have surgery this week.
"It's a tough thing for Ryan," Cardinals coach Ken Whisenhunt told reporters. "The timetable for recovery is probably three months, so that puts him out for the season.
"We didn't think after the game it was going to be the case, but in getting tests done on it and talking to the doctor, it's something that's going to require surgery."
Williams, who lay motionless on the field for several minutes after being hit by Rams safety Darian Stewart, missed all of his rookie season in 2011 after rupturing his patellar tendon during the preseason.
He led the 4-1 Cardinals with 164 rushing yards through the first five games of the season. (Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Frank Pingue)