Can't say that for certain. If McCoy gets going, passing automatically becomes more effective. If this happens and Vick can play mistake free football, they can hang. Those are two very big ifs, but it's their key to a close game.
The Eagles always seem to have the big play in their back pocket as well.
I'm not going to discount their offense, until we see our defense stop it.
What I can see happening, as it has in the first three games, is that Del Rio's gameplan will revolve around stopping McCoy, and shutting down the run. Forces them to pass (especially if Broncos have any lead), pressures Vick. When you can force a team to pass exclusively, it makes them one dimensional. Opens up options for bring different pressures, and plays to the strengths of a strong secondary/fast good coverage LBs like we have.
Same thing that pretty much happened to Baltimore (58 total rushing yards), Giants (23 total rushing yards), Oakland (49 total rushing yards). Forced all of these teams to throw, made their offenses one dimensional, and played to the strengths of the team (secondary/good coverage lbs), and attempted to hide the weaknesses (poor rush generated by DL).
Some of this is obviously generated by having leads in the games played so far, but it's been a consistent thread of the Del Rio defense to absolutely shut down the run if at all possible. Plus it helps turn around the ball to the offense faster if the opposing team can't generate run yards to burn clock. It's complimentary football if you think about.