"Right now, I'm counting on he'll be there, and I know he'll want to be there, so there is a fine line there because this guy is so competitive that he wants to be out there every minute," Reid said during his radio show on WIP-AM (610).

"We just have to make sure the tests come back and he's OK to play," the coach said.

Pennsylvania Hospital's Art Bartolozzi, the former team physician for the Eagles and Flyers, indicated that Westbrook would probably not be able to play Sunday or the following week, when the Eagles are at home against the Dallas Cowboys.

"If he was unconscious, he is probably out at least a few weeks," Bartolozzi said. "The brain is like a computer. Amnesia means the hard drive has been shaken. If you lose data, it tells you something is wrong with the computer."

Reid confirmed that Westbrook was both unconscious and experienced memory loss after taking a knee to the head from Washington Redskins linebacker London Fletcher midway through the first quarter of Monday night's game at FedEx Field.

The coach said it was a frightening moment, but he was relieved that his star running back was unconscious rather than paralyzed.

"That is scary," Reid said. "I think we all felt that. You don't want anybody to get hurt, but you'd rather have a knockout than somebody be paralyzed. Actually, by the time he came back [to the sideline] for the second half, he was really coherent and kind of with things. He didn't remember a thing, but he was with it at that moment."

Reid said Westbrook would undergo a battery of tests from trainer Rick Burkholder that would then be sent to Pittsburgh and eventually evaluated by the Eagles' team physicians. Bartolozzi said the University of Pittsburgh had computer-generated tests to measure the impact of a concussion.

According to the American Academy of Neurology's guidelines, Westbrook suffered a Grade 3 concussion because he lost consciousness and memory. That is the most severe level of concussion, according to the academy.

The Academy's Web site suggests that a player sit out one week after losing consciousness for a brief period (seconds) and two weeks after losing consciousness for a prolonged period (minutes). It appeared as if Westbrook had lost consciousness for at least a few minutes.

"He's OK," Reid said. "He's going to be OK, so . . . it's a matter of time now. We'll see where he's at as we get closer to the end of the week."

Westbrook, of course, has had to deal with his share of injuries during his career, but this is believed to be the first time he has had a concussion. Players that have experienced multiple Grade 3 concussions can be sidelined for as long as a month. Westbrook missed the Eagles' third game of the season, against Kansas City, because he sprained his surgically repaired right ankle.

It appeared as if Westbrook was about to become the focal point of the Eagles' offense again before Monday night's injury. After he accounted for a season high of 141 yards from scrimmage against Oakland, the Eagles called Westbrook's number three times on the first 10 plays against the Redskins. He picked up 13 yards on three running plays.

Rookie LeSean McCoy replaced Westbrook as the primary running back and did not have nearly as much success, running 14 times for 37 yards. Reid said McCoy would start against the Giants if Westbrook was unable to play.

Bartolozzi said it was difficult for players who suffered concussions to maintain their physical condition while they were recovering.

"One of the things that happens with a head injury is that, unlike other parts of the body, exercise does not help the recovery," Bartolozzi said. "It's tough to maintain the fitness because the brain doesn't like a lot of conditioning exercises."

Contact staff writer Bob Brookover at 215-854-2577 or bbrookover@phillynews.com.