Left tackle Trent Williams returned to the lineup for Sunday's game against Green Bay, but he suffered another knee injury and was sidelined on the Redskins' final drive.
Williams is scheduled for an MRI on Monday.
He suffered the injury on the last play of regulation when he tried to make a tackle on an interception return.
Williams sat on the field for several minutes as athletic trainers evaluated his knee. He was able to walk off the field on his own, although he had a noticeable limp.
"My knee kind of gave out on me," Williams said. "It was painful, but we did the [ligament] tests and it looks optimistic."
Remarkably, Williams came out for the Redskins' first series of overtime.
"It hurt a lot, but I just wanted to win," he said. "I did everything in my power to get that win."
Said head coach Mike Shanahan: "I thought he was out for sure. I thought it was really serious. For right now, we're keeping our fingers crossed. I don't think there was any structural damage."
For the Redskins' last series of the game, Williams was replaced by Stephon Heyer.
Last week, Williams was limited in practice due to a lingering toe injury. He was listed as questionable heading into the Packers game.
Williams returned to action after missing the previous two games with knee and toe injuries.
Williams started next to Kory Lichtensteiger for the first time. Lichtensteiger replaced Derrick Dockery in the starting lineup two weeks ago in St. Louis.
Dockery was among the Redskins' inactives for the Packers game. Will Montgomery, who has more versatility than Dockery, served as the Redskins' backup interior offensive linemen.
-- BROWN HAS KNEE INJURY, TOO
Right tackle Jammal Brown left the Packers game in the first half with a knee injury.
Mike Shanahan said there appeared to be no structural damage to Brown's knee, but Brown was scheduled for an MRI on Monday.
Brown was initially replaced by Stephon Heyer.
In overtime, after Trent Williams went down with a knee injury, Heyer moved to left tackle and Artis Hicks shifted to right tackle. Will Montgomery took Hicks' spot at right guard.
At game's end, only center Casey Rabach and left guard Kory Lichtensteiger remained from the starting offensive line.
Derrick Dockery was inactive for the first time in his 8-year career. He was replaced in the starting lineup by Lichtensteiger in Week 3.
-- HAYNESWORTH IN NASHVILLE FOR FUNERAL
Defensive lineman Albert Haynesworth attended his brother's funeral in Nashville on Sunday.
Haynesworth's brother Lancy McCoy died in a motorcycle accident last Thursday and Haynesworth left the Redskins to be with his family.
The family held a memorial motorcycle ride in honor McCoy on Sunday in Nashville.
Haynesworth was among the Redskins' inactives for Sunday's game against Green Bay.
It's uncertain when he is expected to return to the team. His family has scheduled a service in South Carolina on Tuesday.
-- JARMON ACTIVE FIRST TIME THIS SEASON
With Albert Haynesworth inactive, defensive end Jeremy Jarmon played in his first game this season.
Jarmon was seeing action for the first time since Week 12 last year when he suffered a torn knee ligament.
Jarmon played in preseason this year but was inactive the first four regular season game.
Coaches have been cautious with Jarmon during preseason and the first four regular season games. They wanted to make sure the knee was sound before giving him extensive playing time.