Chip Kelly adds variety in Eagles backfield

Chip Kelly doesn't use many running backs unless he really has to.

If you can carry the ball continually and for positive yardage, he pretty much lets you do it until you drop.

When he assumed the head coaching position of the Eagles, there was a plentiful selection of tailbacks on his roster, all decently talented. But it was LeSean McCoy who got the lion's share of carries: 314 rush attempts in 2013, the most in football, and only two less the following year. 

McCoy left for Buffalo the Eagles' all-time leading rusher for his trouble.

Even after Darren Sproles had a gangbuster's start to 2014, Kelly slowly nudged the ball out of his hands and back into McCoy's, where it largely stayed.

That point of view can come back to haunt a coach and his team, with all players at every position, in theory, one injury away from oblivion. 

"We probably relied on one [running back] too much the last couple of years," Kelly said.

So he overhauled the backfield much the same way he did the defensive secondary, linebacking group, and quarterback position. DeMarco Murray, who led the NFL in rushing yards and touchdowns in 2014 with the Cowboys, and Ryan Mathews were brought over in the free agency period.

"I have great confidence in those guys," he said. "When they go in a game, you don't have to change what you're doing. Ryan and DeMarco are very similar in terms of how they run and what they're doing. You think you'll catch your breath when you get DeMarco out of a game but then here comes Ryan. That's going to be a really difficult match for people."

Running back depth was something that eluded Kelly at Oregon. In his first season in charge of the Ducks, Jonathan Stewart led the team in rushes, followed by his quarterback, Dennis Dixon. LaMichael James had the team largely to himself in 2009 after LaGarrette Blount threw a punch in the Ducks' first game. James was followed again by his quarterback, this time Jeremiah Masoli.

Kelly leaned heavily again on James in 2010 for 294 rushes, with backup Kenjon Barner's 91 rushes far behind. Barner edged closer the next season, before taking over in 2012, with quarterback Marcus Mariota the No. 2 ball carrier.

That sort of domination and single-mindedness at the position, and the reliance on the quarterback to supply enough secondary rushing yards of his own, can be a winning formula in college. But the NFL is another matter, as Kelly heard endlessly when he brought his "peculiar" offense to the professional ranks to the skepticism of so-called experts.

But Chip Kelly seems to be changing his view this season. Sproles remains from 2014, and can be a speedy, elusive wild-card catching passes from the backfield and zooming downfield on screen plays behind blocks. 

He'll be the No. 3 option behind Murray and Mathews. That's a threesome that will almost guarantee the Eagles don't produce a single-season rushing leader, but it will provide a much-needed balance that could age both their main backs a little slower and fend off those injuries that come with an every-down rusher.