The man responsible for handling the rotation is Duce Staley. In a clear sign of trust, Chip Kelly defers to his running backs coach to decide who is in and for how long during the course of a game. Staley explained his approach to that responsibility.
"I just go in with an open head and make sure I don't get caught up in the last game," he explained. "I try to get a good feeling of what's going on out there and then I go from there. I think there's too much put into it when you start sitting down and writing out a plan. You get in trouble that way."
So it's all by feel?
"I don’t think it’s very difficult," said Kelly. "I think Duce always does a really good job, depending on who is available to him, in terms of rotating those guys in. The biggest thing for us is we just want to keep someone fresh in the game. So if it takes getting you out for a couple of plays, just to get you wind and get you back, it takes a toll on the defense. So you can take Ryan Mathews out and DeMarco Murray comes in; or if DeMarco Murray comes out and Darren Sproles comes in. That’s kind of what we have been trying to build towards here and those three guys obviously give us the opportunity to do that."
One beat writer predicted a 50-30-15 split among Murray, Mathews and Sproles, with the rest of the carries divvied up among the quarterbacks and receivers. The Eagles averaged 487 carries over the last two years, so if Murray sees 50 percent of the carries, he's looking at around 244 carries. We project him to carry the ball 259 times this year, so we feel the backfield will tilt slightly more in his direction. Still, workload is a concern with Murray after he was the bell cow of all bell cows in 2014.