It is the ankle, on which he had surgery in June. That cost him training camp, the preseason and Game 3 of this season, all before the concussions occurred.
The past 2 months might have given the ankle more time to heal, but it hasn't been appreciably strengthened, since part of the prescription for concussion recovery is total rest.
"I didn't have the opportunity to work out the way I usually do in the offseason," Westbrook said. "I don't think that time off really helped in that manner, because I didn't get a chance to work out as much as I wanted to, either."
So, as the Eagles enter the final week of their season, they have a Westbrook with fresh legs, if not good wind, and the sort of tempered strength that is produced by months of exercise and hitting.
Eagles coach Andy Reid committed to nothing regarding Westbrook's workload Sunday in Dallas, even after Westbrook led the team with nine carries Sunday, if only for 32 yards, as the Broncos keyed on him whenever he hit the field. Dallas plans the same sort of treatment:
"He's a player you have to account for when he's on the field," Cowboys coach Wade Phillips said.
Whether his ankle, or the rest of him, is wholly potent or not.
Donovan McNabb has had an outstanding season despite missing two games. He has led the Eagles on a dominant late-season run into the playoffs, where they have a shot at the No. 2 seed and the NFC East title. It is, possibly, the second-best of his 11 seasons, five of which ended with trips to the Pro Bowl.
This one could, too - he's the NFC's first alternate - but he didn't expect even that, what with the amazing years by Drew Brees, Brett Favre and Aaron Rodgers, all of whom were named to the NFC squad.
"It's still funny to me that I was a first alternate. I just didn't see that happening," McNabb said. "For me missing two games . . . and the numbers that these other guys have put up, I just really didn't see it. So again, my main focus is to get to Miami and the next week, not in that week."
The Pro Bowl will be played Feb. 1 in Miami; the Super Bowl, a week later.
Wade Phillips, on whether he would assign one defender to cover Pro Bowl wideout DeSean Jackson, as the Broncos did Sunday: "No. We're going to put two on him all day" . . . Phillips acknowledged that the Eagles have been creative in their deployment of Jackson since the Cowboys shut him down Nov. 8 (two catches, 29 yards). *