ASHBURN, Va. – The Washington Redskins returned to an unwanted and familiar spot: dealing with a season-ending injury to a starter.

For the sixth time this season, the Redskins have been forced to answer questions about losing a key starter after corner Chris Culliver injured his knee in practice Thursday.

Culliver tore the ACL and MCL in his right knee during practice Thursday and was placed on injured reserve Friday. He joins other starters whose seasons ended prematurely: tight end Niles Paul, linebacker Junior Galette, safety Duke Ihenacho, guard Shawn Lauvao and center Kory Lichtensteiger (though he can return for the playoffs).

“He’s a good player for us,” Redskins coach Jay Gruden said. “You hate to lose good players. Unfortunately it happened, a fluke deal. … [Secondary coach Perry] Fewell has been schooling these other guys up. That’s what pro football is all about. You hear all the time next man up and that’s the way it is. We’re very sad for Chris. We’ll miss Chris quite a bit, but other guys have to step up and play. We don’t have any other choice. These guys are ready, they’ve been eager and they’re ready for their opportunity to play, and they’re going to get it.”

The Redskins’ secondary has dealt with one injury after another this season -- as well as two one-game suspensions. It’s led to a lack of continuity, but also a forced versatility.

It didn’t help Friday that corner Bashaud Breeland missed practice because he was sick; Gruden said he had a fever. He’s listed as questionable.

The Redskins have to fill Culliver’s roster spot and could promote corner Dashaun Phillips off the practice squad. On the field, Will Blackmon could end up starting opposite Breeland, assuming he’s not still sick. They also can use Quinton Dunbar. DeAngelo Hall’s role might be more at safety at this point.

“We have a couple options,” Gruden said. “We have a lot of versatility back there. If there is a saving grace with all the injuries we’ve had, we’ve had to try to intermingle everybody in different spots. They all have a good knowledge of nickel, corner, safety. So we’ll have it covered.”

Hall said: “We have so many guys moving around in so many situations the last couple games it’s going to be interesting who they ID at what position because we’ve all played a little of everything. “

But the Redskins will rely on the veteran Blackmon, who can play inside or outside at corner; Kyshoen Jarrett can play nickel corner or safety; Hall now can play outside at corner or safety.

“Whatever they tell me to do or need me at, that’s what I’ll do,” Hall said.

The Redskins now have 11 players on injured reserve this season, with 10 having a good chance to be on the roster this season. A 12th player, Lichtensteiger, was placed on the designated to return injured reserve.

Blackmon joined a similar situation in 2010 when he joined the New York Giants in late November. Their secondary was banged up, and they had a number of players on injured reserve -- yet still beat New England to win the Super Bowl.

“You just have to make sure you’re training your depth,” Blackmon said. “That’s the most important part. You have faith that the veterans will be professionals and do their job and train their depth so when their number is called they’re ready to go.”

In other injury news, safety Trenton Robinson won’t play Sunday because of a hamstring injury. Left tackle Trent Williams is questionable with a knee injury, but it would be surprising if he doesn’t play. The Redskins have been optimistic all along about his availability and nothing has altered those plans. Linebacker Keenan Robinson (shoulder) is questionable, though he’s unlikely to play.