"On Friday afternoon, Brian began experiencing symptoms of a mild headache," Eagles head athletic trainer Rick Burkholder said in a statement released by the team. "From that point forward, we had Brian re-evaluated by [team internist] Dr. Gary Dorshimer, and we put him through extensive testing. Even though those tests were determined to be negative, we all thought it would be in the best interests of Brian and the team that he should be deactivated for tonight's game. We will continue to evaluate Brian this week."

Westbrook's agent, Todd France, did not respond to requests for comment yesterday from the Daily News.

When Westbrook didn't play against the Giants, the Eagles said his tests were normal but they decided to be cautious with a player who was briefly knocked out cold when the knee of Washington's London Fletcher struck his head. Westbrook practiced Wednesday and Thursday last week, but was held out of practice Friday morning, and later was listed as "questionable," which seemed a more pessimistic assessment than the ones offered earlier in the week. But Eagles coach Andy Reid said Westbrook was held out to give rookie LeSean McCoy some first-team reps. Reid told reporters Westbrook had not suffered a setback.

"He felt good during the week," Reid after last night's game. "He practiced during the week. It's a crazy deal . . .

"I know this: If he has [headaches], I'm going to go more on the conversative side and take every precautionary measure possible. I'm not going to stick him out there, even if the tests are positive."

As for Westbrook's prognosis for San Diego, Reid was noncommital: "We'll just see how he does this next week."

At his Wednesday news conference, Westbrook said he was "excited about the opportunity to play again," but he also talked about the uncertainty involved in dealing with concussions.

"It's been trying times. It's tough, because, never having a concussion before, you never really have a time period," Westbrook said. "You're not sure if it's going to be 2 weeks or 1 week. You're not sure exactly what it's going to be. You just hope and pray that the symptoms will go away."

Along those lines, there is no way to know that Westbrook's headaches will not return, this week or even in the wake of contact whenever he does play again. When Westbrook was injured, in the first quarter of the Redskins game, he seemed to finally be shaking off the rust from missing the preseason because of ankle surgery, then tweaking the ankle in Week 2 against the Saints.

Scare for Peters

Left tackle Jason Peters injured his left ankle when his leg was rolled up on by Jay Ratliff when he was sacking Donovan McNabb late in the first quarter. Left guard Todd Herremans moved to left tackle, Nick Cole moved from right to left guard, and Stacy Andrews came in for Cole at right guard.

On the next play, Herremans was called for illegal formation for not being on the line of scrimmage. On the next drive, Andrews gave up a sack to Ratliff, killing the Birds' drive and making a 45-yard David Akers field goal tougher than it should have been.

Peters had the ankle X-rayed and returned late in the second quarter.

Birdseed

It was not surprising that strongside linebacker Chris Gocong was unable to play against the Cowboys. Gocong did not practice last week and was listed as "doubtful" with quad and hamstring injuries. Gocong had played in 39 successive regular-season games, every one since he missed his rookie season of 2006 with a neck problem. Seventh-round rookie Moise Foukou started for Gocong . . . Also inactive were corner Dimitri Patterson, o-linemen Max Jean-Gilles and Mike McGlynn, defensive end Victor Abiamiri, wideout Kevin Curtis and running back P.J. Hill. The Eagles chose to fully activate all three quarterbacks . . . Safety Quintin Demps left the game because of an ankle injury.