Part Five of an online-only series

Eagles coach Chip Kelly ran the ball around 60 percent of the time during his four seasons as head coach at Oregon. Does that mean he plans on calling on his running backs as much as he did in college? Probably not. The NFL average for run-pass ratio was around 42-58 last season. It's still a passing league.

With that in mind, here is a look at the Eagles running backs:

Projected first team

RB1: LeSean McCoy (5-foot-11, 208), age 24, 5th season

RB2: Bryce Brown (6-0, 223), 22, 2nd

Three teams went to the ground more than the air last season. And all three teams - the 49ers, Seahawks and Redskins - made the playoffs. They, of course, featured mobile quarterbacks and offenses that utilized the read option. The read option was Kelly's bread and butter at Oregon, but that didn't necessarily mean his quarterbacks ran a whole bunch. His running backs, though, got a boatload of carries, partly because of play-calling but also because of the Ducks' up-tempo offense.

So what does that mean for the Eagles tailbacks? Kelly's plans remain a mystery, but using deductive reasoning it's safe to assume that McCoy, Brown and company will get more action than they did under Andy Reid. McCoy could thrive in Kelly's college system, which had zone blocking schemes designed to create space for his running backs. McCoy thrives in space. Kelly likes to use his running backs just as much in the passing game. I think we've yet to see McCoy tap into his full potential as a ball catcher.

After an all-pro 2011 season, McCoy wasn't as productive last season. The injuries on the offensive line certainly didn't help, and he did miss four games with a concussion. But there was something missing from his game: touchdowns. After reaching the end zone 20 times in 2011, McCoy scored only five times in 2012. A good thing is that McCoy is said to have gone into spring workouts in perhaps his best shape ever. He still has something to prove. He could have a blockbuster season.

The backup spot, which would more of a complementary role, is Brown's if he can hold onto the football. He dazzled in his first two starts for the injured McCoy - rushing for 178 and 169 yards, respectively, and two touchdowns in each game. But he also turned the ball over three times. Brown was more careful in his next two starts, but he did little with the ball. There's obvious talent there, a rare combination of speed and size, but he's still raw. Brown told me last month that he worked on his ball security issues this offseason by carrying around a weighted football. We'll see if it worked.

Second team

Felix Jones (5-10, 215), 26, 6th; Chris Polk (5-11, 222), 23, 2nd.

The Eagles brought in Jones as insurance, but they also think that he can make the team and contribute. The former Cowboys running back has five seasons under his belt, but he also just turned 26. Jones always seemed to have some nagging injury in Dallas. He played in all 16 games last season, but finished with a career-worst 3.6 yards a tote. He's always been effective in the screen game. Kelly could find ways to get him involved in the offense. Polk did not log a carry or catch as a rookie last season. He mostly played special teams until a foot injury slowed him down. He appears to have gotten rid of some of the baby fat he carried last season. Kelly has spoken well of Polk this offseason. Kelly won't carry a fullback, and you still need someone to get those tough yards in between the tackles.

Others

Miquel Maysonet (5-9, 209), 23, rookie; Matthew Tucker (6-1, 227), 21, rookie.

Kelly isn't likely to carry more than four running backs on the 53-man roster, but Maysonet and Tucker could earn spots on the practice squad. Maysonet will miss the rest of spring workouts because he has yet to graduate from Stony Brook.