Arizona Cardinals running back Ryan Williams will undergo shoulder surgery this week and miss the remainder of the season.
Williams sustained the injury in Thursday night's loss to the St. Louis Rams. The second-round pick in 2011 also missed his entire rookie season with a torn Achilles' tendon.
"It's a tough thing for Ryan," Cardinals head coach Ken Whisenhunt said. "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 (Sunday), it's something that's going to require surgery."
Whisenthunt said the three-month timetable to return precludes Williams from playing again this season.
"I feel horrible for Ryan," Whisenhunt said. "What I told Ryan when we sat down was that at least this time he won't have to deal with it through an offseason. He'll be able to go through an offseason program, he'll be able to go through practices. That'll get him in better shape to be ready to go for next year."
With Beanie Wells out, Williams had been getting the bulk of the carries. He had 58 rushes on the season before the injury, but was only averaging 2.8 yards per carry.
Wells is on injured reserve with turf toe but is designated to come back as of Nov. 25. LaRod Stephens-Howling is also hurt and his status for Sunday's home game against the Buffalo Bills is uncertain.
William Powell and recently-signed Alfonso Smith look to factor into Arizona's running game if Stephens-Howling cannot play.
"I feel good about the guys that we've got," Whisenhunt said. "We're always going to look to get better at every position and if that opportunity is there, then we'll certainly try to act on that."