As Washington running back Evan Royster grabbed at his leg in pain on Sunday afternoon, Redskins coaches feared the worst for the team's third-string running back, fullback and special teamer.
On Monday, head coach Mike Shanahan confirmed that the injury, a high ankle sprain, would be season-ending.
"Evan Royster will be out for the season," he told the media. "Unfortunately his injury will be more than three weeks, so he will go on IR.
"We haven't made a decision yet who we're going to bring up."
After a stellar preseason, Royster's workload decreased with the healthy return of Roy Helu Jr. to the lineup. He finishes the season with two carries for zero yards and one catch for three yards.
He did not start the Week 13 contest vs. San Francisco, but was the team's primary fullback with Darrel Young and Niles Paul out of the lineup.
He was also a regular contributor on special teams this season, collecting four tackles in coverage.
High ankle sprains, typically considered the more serious variety of ankle sprains, occur when a player damages the ligaments above that ankle that connect it to the tibia and fibula.
These injuries are much less comon than sprains to the ligaments on the outside of the foot. They also take more time to heal, usually in the range of six-seven weeks.
With only three weeks left in the season, there was little chance that Royster would be available before Week 17. He will be placed on season-ending injured reserve and the Redskins will look to fill his spot on offense and special teams.
Currently, the Redskins have only two other running backs on the roster, with Alfred Morris and Roy Helu Jr.
The Redskins have two running backs on the practice squad, with both Jawan Jamison and David Meggett available for promotion. The Redskins could also take a flyer on a running back in free agency as well.
The Redskins go into Week 15 with a host of starters and valuable contributors on injured reserve: Stephen Bowen, Dezmon Briscoe, Adam Carriker, Richard Crawford, Leonard Hankerson, Maurice Hurt, Bryan Kehl, Jeremy Kimbrough, Keenan Robinson, Nick Sundberg, Phillip Thomas, Chris Thompson and Doug Worthington.