Quarterback Mark Brunell suffered a sprained knee ligament early in the third quarter of Saturday's 35-20 win over the New York Giants. He was replaced by backup Patrick Ramsey.
Brunell's status for practice this week and next Sunday's game against the Philadelphia Eagles will be determined early next week, team officials said.
"We'll have to see how it develops in the days ahead," head coach Joe Gibbs said after the game. "Mark tried to come back off of it, but couldn't."
Brunell was injured on a sack on the Redskins' first offensive series of the second half. He was sacked by blitzing linebacker Nick Greisen and laid on the ground for several minutes as trainers evaluated his knee.
Ramsey immediately began to warm up. Minutes later, Brunell joined him on the sidelines, testing his knee. But it was Ramsey who went into the game.
Ramsey, seeing his first action since mop-up duty in the Week 8 game loss to the Giants, completed his first pass of the game to running back Ladell Betts. He was forced to call two time outs on the series when there appeared to be some miscommuncation among the offensive players.
Then lightning struck. Ramsey threw a deep pass to Santana Moss, who caught the pass ahead of cornerback Will Allen and broke free for a 72-yard touchdown. The score gave the Redskins a 28-17 lead.
Ramsey also led the offense on a touchdown drive in the fourth quarter. He threw several passes to Cooley and also completed a key third-down throw to Moss.
Running back Clinton Portis finished off the drive with a 19-yard touchdown run, skipping past Allen to break down the left sideline. Portis out-raced every Giants defender to the goal line, giving Washington a 35-20 lead.
Ramsey finished the game completing 5-of-7 for 104 yards and one touchdown.
"We've talked all year and I've told him he's one play away," Gibbs said. "He's in one of the most important positions on our football team. That's the reason we put a lot of attention into our quarterbacks and the depth we have here.
"Here is one of the biggest games I've ever been in and Patrick has to go in and win it for us. I've appreciated how Patrick has handled the situation all year. It says a lot about him and his character. He stepped in amd made some plays."
Added Ramsey: "It was a big win for us. Everyone really stepped up when I had the opportunity to go in. All the guys played great, which made it pretty easy on me."
Brunell was solid in the first half before his injury. He completed 7-of-11 passes for 112 yards and two touchdowns, including a 59-yard TD pass to Moss.