Troy Aikman could miss the rest of the season with a torn collateral ligament in his right knee.
The Dallas Cowboys quarterback, who suffered a separated shoulder in last year's playoff drive, "is expected to be out of action for three to four weeks," the team said.
Doctors said "no surgery is recommended and a conservative course of treatment will be put into place immediately."
Coach Jimmy Johnson said backup Steve Beuerlein, who led the Cowboys to their victory over Washington, will start even though he's limping with a sprained left ankle.
The Cowboys floundered badly under backup Babe Laufenberg last year after Aikman was injured on a tackle by Clyde Simmons. Dallas lost its playoff chances in a season-ending loss to Atlanta.
Dallas expects a better ending this time.
"A year ago, we were flat when Aikman went down," Johnson said. "We think we can win with Beuerlein."
Laufenberg was cut in training camp and Johnson obtained Beuerlein from the Raiders on Aug. 25. Beuerlein started 15 games for the Raiders but drew the ire of Al Davis in a contract dispute.
Johnson got Beuerlein for a 1992 fourth-round draft pick.
Aikman was injured in Sunday's 24-21 victory over the previously unbeaten Redskins when he was tackled by Charles Mann with 12 minutes, 54 seconds left in the third quarter.
"It still hurts," Aikman said. "I can't even backpedal. I don't see how there would be any way I could play."
Backing up Beuerlein will be Craig Kupp, a rookie from Pacifi Lutheran who was obtained on waivers Nov. 7 a day after he was cut by Phoenix.
* COLTS: An unrepentant Eric Dickerson rejoined Indianapolis, but left no doubt he would rather be somewhere else.
Dickerson was fined and suspended for refusing to practice earlier this month.
"I'm here to do my job, and that's it," he said yesterday, his first day back after three weeks in exile.