You want to survive a season in which your quarterback misses significant time due to injury? It's not about winning with a backup quarterback, it's about winning without an elite quarterback. The Ravens did it with Trent Dilfer, the Bucs did it with Brad Johnson and the Redskins did it three times with good but not great quarterbacks. What did they have in common?
A running game.
The Eagles have the potential to have a really good running game. They have one of the best running backs in the game, LeSean McCoy, and a couple of good young backs in Dion Lewis and Bryce Brown.
McCoy gets all the love from fans and critics alike for his ability to make people miss in the open field, but he is a little underrated as a power runner. According to Football Outsiders, McCoy leads the league in broken tackles with 50. His strong lower body and quick feet make him a complete back.
Dion Lewis is a similar player to McCoy, also possessing quick feet and a strong lower body. He isn't nearly as polished as McCoy is, but he can be a nice compliment to him for five or six carries a game.
Bryce Brown isn't a similar player to McCoy and Lewis. He is a bigger back at 6'0", 220, and he has more straight line speed, running a 4.37 at his pro day last spring. He is more comparable to Adrian Peterson than he is LeSean McCoy. He has to make the roster first as a seventh round draft pick, but if he does, the Eagles could have three really good running backs to hand the ball off too.
The key to a successful running game these days isn't one dominant back, it's two or three really good ones. You want to spread the carries around multiple backs so you can keep them fresh throughout the game and season.
The Eagles have the players to be a successful running offense. There is no reason why the Eagles should be running any less than 30 run plays a game. A solid running game keeps your quarterback upright and takes the pressure off of a backup quarterback when the starter is out.