ASHBURN, Va. -- The Washington Redskins are shuffling their lineup again after losing their strong safety and right tackle to multiweek injuries.
In addition, Clinton Portis is recovering from a concussion and is doubtful to play in next week's game against Denver.
Safety Chris Horton damaged a ligament in his left big toe during Sunday's 31-17 loss to Atlanta. He's out a minimum of four to six weeks -- and it will be four to six months if a specialist decides the toe needs surgery.
Offensive lineman Mike Williams, who has started the last four games, is out two to four weeks after tearing a ligament in his ankle. He will also see a specialist but doesn't expect to require surgery.
Portis took a helmet-to-helmet blow as he was tackled at the end of a running play during the first quarter on Sunday. He will undergo a test Tuesday to help determine his availability for the Broncos game.
"He still doesn't remember the play," coach Jim Zorn said Monday. "We have to be very cautious with a concussion."
Zorn said season-ending injured reserve is a possibility for both Horton and Williams. The Redskins are already without left tackle Chris Samuels and right guard Randy Thomas, both on IR, and tight end Chris Cooley is out at least two more weeks with a broken ankle.
Zorn said Stephon Heyer will move back to right tackle and that Levi Jones, who was signed three weeks ago, will start at left tackle against the Broncos. It will be the fifth different starting offensive line alignment used by the Redskins (2-6), who have lost four straight.
"I'm concerned about all of our injuries, no question about it," Zorn said. "It's what teams have to deal with each week, and we've absolutely had our share, but one of the things that we will do is we'll be competitive. We'll go out and compete, and we'll put out there our best effort, the best guys we can get in this program, and put them on the field."
The Redskins will look at signing a safety and a running back. Zorn said the team had a discussion about Larry Johnson, who was released by Kansas City on Monday, and would revisit the possibility later.
Zorn said Jason Campbell, who left Sunday's game twice while getting battered behind the patchwork offensive line, has a sprained ankle but will remain the starting quarterback against the Broncos. Portis' backup, Ladell Betts, also has a sprained ankle but is expected to start if Portis can't play.