A UPMC spokesperson could not be reached for comment last night, so it was unclear how the doctors define "full recovery."

In Sunday's loss in San Diego, Westbrook suffered his second concussion in 20 days when he was tackled after a third-quarter screen pass. That concussion apparently was not as bad as the one he suffered Oct. 26 in a game against Washington, but concussions can cause cumulative damage. That calls into question when or whether Westbrook will ever return to play for the Eagles.

Westbrook declined comment after Sunday's game and could not be reached for comment yesterday.

UPMC's statement said Westbrook had several "neuro-cognitive tests, including IMPACT™ (Immediate Post-Concussion Assessment and Cognitive Testing), a computerized tool that is used by all NFL teams for evaluating injury recovery. He also underwent comprehensive physical and neurological exam, results of which were favorable."

Maroon is a UPMC neurosurgeon and longtime neurosurgeon for the Pittsburgh Steelers. Collins is a UPMC neuropsychologist at the UPMC Sports Medicine Concussion Program. Mark Lovell, the program's director, was also involved in Westbrook's care, according to the statement.

"We commend the Eagles athletic training and medical staff for their diligent and conservative care in this particular case as well as their historical excellence in managing these types of injuries," Lovell said.

Eagles coach Andy Reid said yesterday he last spoke to Westbrook on Monday.

"He was in a good place," Reid said. "I think that he's grateful to have had the care that he's had. He seemed to just want to find out what went on with this [second concussion], but he didn't seem rattled."

Quarterback Donovan McNabb showed the proper concern for Westbrook but later suggested the Eagles have a "must-win game" Sunday at Chicago's Soldier Field.

And they do.

After consecutive losses to Dallas and San Diego, the 5-4 Eagles will try to avoid their first three-game losing streak since November 2007. They are playing a Chicago team that has lost four of its last five but is 3-1 at home this season, including a win over the Super Bowl champion Pittsburgh Steelers.

"This is a game we need to win," McNabb said. "That's the way I'm approaching it, and that's the way the other guys are approaching it as well."

With Westbrook out, rookie LeSean McCoy probably will make his fourth start of the season. Reid said he opted against adding a running back to the roster because he thought fullback Leonard Weaver could share the workload at tailback.

The Eagles' coach also holds out hope that Westbrook will return this season.

Weaver "has versatility to where he can also be a ballcarrier, and he's good in the pass game and so on," Reid said. "His versatility allows me not to make a move at this particular time. Plus, I don't really know the outcome of what they're going to say on Brian, so I just have to see as time goes on here."

Bears coach Lovie Smith seemed relieved to hear that Westbrook would not play.

"Whenever you lose a special player like that, you can't be as strong," Smith said. "But a lot of times when one good player can't go, another one will step up, and I'm sure that will be the case. McCoy is a good football player, and they have other weapons. But our chances are better without Westbrook."

In the two games he knew he was going to start at tailback and spent the entire week practicing with the first-team offense, McCoy ran 31 times for 166 yards, an average of 5.4 yards per carry.

In the Eagles' other seven games, he has run the ball 55 times for 145 yards, 2.6 yards per carry.

"I think when anybody gets enough reps during the week they're more comfortable," McCoy said. "I never expected to have to play a big role like this . . . but, hey, I was drafted for a reason."

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