Richardson, who has been dealing with a bad right shoulder all season, aggravated a knee injury vs. Carolina on Sunday. Crowder will miss his second consecutive game because of a sprained ankle that could sideline him longer. On Thursday, Crowder was seen outside the locker room with a boot on his right foot and using a scooter to get around the facility.
"For a slot receiver to change directions with confidence, we'll have to wait and see," Redskins coach Jay Gruden said. "I would expect him to be back sooner than later, but it could take a little time."
There's also concern about running back Chris Thompson, who missed last week with rib and knee issues. He's listed as questionable and likely will be a game-time decision. Running back Adrian Peterson also is questionable, with knee and shoulder injuries, but is more likely to play.
Richardson visited a doctor Thursday, and Gruden said there was nothing structurally wrong with his knee, which he first hurt vs. New Orleans in Week 5. Gruden said they're trying to figure out a way to "relieve the irritation" for him.
Richardson has been Washington's most productive receiver, with 16 catches for 212 yards and two touchdowns. In three games, Crowder has caught 13 passes for 134 yards and a touchdown. Washington's wideouts have combined for 75 targets -- fewest in the NFL, according to ESPN Stats & Information.
The Redskins will replace Crowder in the slot with Maurice Harris. The Redskins can replace Richardson with veteran Michael Floyd, who has yet to catch a pass. Floyd has played a combined 16 snaps in two games. Veteran Brian Quick also would become a bigger part of the game plan. This scenario does give Washington a more physical receiving corps.
Washington also can use more of its two-tight-end set. In the Redskins' three wins, they've averaged 28.3 snaps per game with at least two tight ends. Jordan Reed's and Vernon Davis' ability to line up in the slot or run routes out of the backfield provides versatility for Washington's offense. If Thompson can't play, Kapri Bibbs would serve as Washington's third-down back. Last week, Bibbs rushed twice for 11 yards and caught one ball for 6 yards.