Eagles' roster analysis: Running backs

PHILADELPHIA -- With the traumatic free agency period and the NFL draft behind us, we’re taking a position-by-position look at the Philadelphia Eagles' roster. Next up: the running backs.

Running backs

Nothing was more traumatic this offseason than Chip Kelly’s decision to trade LeSean McCoy and his contract and sign a couple of backs to share his workload. Not only was McCoy the Eagles’ all-time leading rusher, he’s a volatile personality who struck back at Kelly with a series of provocative interviews.

With all that said and done, the Eagles are well stocked at the running back position. If the offensive line stays healthy, the running game should be very good. Of course, we could have said that before all the upheaval.

The star: It might help the Eagles that they took DeMarco Murray away from the Dallas Cowboys. But really, this move has to be about what Murray brings to the Eagles, not what he has removed from the Cowboys.

The concern is real. Murray carried the ball 392 times last season, tying him for the seventh most rushing attempts in NFL history. His backup, Joseph Randle, carried the ball just 51 times.

The last back to carry the ball 392 times -- Miami’s Ricky Williams in 2003 –- never reached 250 carries in a season again. After his 392-carry season, Williams managed just 174 carries over the next four seasons combined. Williams was 26 in 2003, the same age Murray was in 2014.

There are plenty of examples of backs who declined sharply after a season with a heavy workload. Since Murray had not been able to play a full 16 games in a season until 2014, it is doubly worrisome. Kelly has said he wants to break up the workload. The trick is sticking with that plan during the season, when you’re trying to win every game.

The supporting cast: That’s where Ryan Mathews comes in. The Eagles signed Mathews, who was able to play in all 16 games just once in his five seasons with the San Diego Chargers. Mathews’ best season was in 2013, when he carried the ball 285 times for 1,255 yards. A year later, Mathews was able to play in just six games. He carried the ball 74 times for 330 yards.

Darren Sproles, who went to the Pro Bowl for his special teams performance last season, will be back. Sproles carried the ball 11 times in the season opener last year. He carried the ball 12 times in the entire month of December, as Kelly reduced Sproles’ workload.

With Murray and Mathews sharing the primary running back role, Kelly should be able to develop a more regular role for Sproles.

Matthew Tucker and Kenjon Barner are still on the roster and will have a chance to take the roster spot vacated by Chris Polk. Undrafted rookie Raheem Mostert, from Purdue, has sprinter speed and should be worth keeping an eye on.

Looking ahead: Kelly knows all about the history of running backs who experience sharp declines after workhorse seasons. He said he plans to split up the carries among Murray, Mathews and Sproles. Keeping the two primary backs healthy will be a major point of emphasis this season.

Say what you will about McCoy, but he played in all 33 games Kelly has coached in Philadelphia, including one playoff game. McCoy carried the ball 647 times in those 33 games. That is the definition of reliability.

If McCoy was too concerned with faking out defenders with shifty moves, that flaw also produced some memorable long runs. Kelly likes the way Murray and Mathews attack the correct hole, make a cut and keep going. We’ll all have a chance to see how that works this season.