When Donnel Pumphrey was at San Diego State, defenders dreaded the prospect of trying to tackle the elusive, 5-foot-9, 176-pound running back in open space.

"In all my years of coaching, he just has an uncanny ability to set guys up and make them miss,'' Aztecs offensive coordinator Jeff Horton said. "He's a phenomenal make-you-miss runner —  making them think he's going outside, then cutting back to the inside.

"I speak at clinics and take the tapes [of Pumphrey] with me and always say, 'That's my cut-through-the-inside-arm drill, and that's my outside-lean-to get-back-inside drill.' But it's all [nonsense]. He just does it naturally. But I would sell it like it was drill work we were doing.''

Pumphrey, who broke the FBS career rushing record with San Diego State (6,405 yards) and also finished with an FBS-record 7,444 yards from scrimmage, made who-knows-how-many tacklers miss during his college career.

But it didn't take the rookie fourth-rounder very long to realize he's not in the Mountain West Conference any longer.

Twelve minutes into the Eagles' first preseason game against Green Bay, Pumphrey took a quick flare from quarterback Matt McGloin and found himself one-on-one in the right flat with Packers second-round pick Josh Jones, a safety. Pumphrey needed 4 yards for a first down. Jones held him to 3.

A couple of minutes later, the Eagles ran a screen to the right side to Pumphrey that gained just 1 yard.

It's a big adjustment between college and the NFL, he said. "I have to get up on people [here] and then make the move, instead of making moves in space like I did in college. If you make moves in space here, they're not really going to move.''

It's all part of the rookie learning experience. In the Eagles' first two preseason games, Pumphrey has rushed for just 2 yards on seven carries and has seven catches for 32 yards.

Five of his seven carries have gone for zero or negative yards. Just three of his seven receptions have gained more than 3 yards. He also has returned six punts for only 14 yards. But that's why they have the preseason.

"He's a guy we've asked a lot of,'' coach Doug Pederson said. "He's a dual-position guy. He's a runner. He's a slot receiver. He's a punt returner.

"He's doing a good job. He's working through our offense and learning it every day. I think he's in a good spot. I'm excited to get him some more touches in the next couple of games.''

Running backs coach Duce Staley said he's no more concerned by Pumphrey's numbers in the first two preseason games than he is by LeGarrette Blount's (17 yards on 9 carries).

While Pumphrey had minus-3 yards on three carries last week against Buffalo, he did catch two passes for 20 yards, and even made a Bills linebacker miss on one of the receptions.

"Pump is doing well,'' Staley said. "Being in the NFL, talking about the volume [of plays] as far as dealing with all of the plays, I think he's catching on well.

"I think he made progress in the last game. You saw him turn the corner after he caught a little wide [pass] out of the backfield and make a guy miss and get up the sideline. The speed is there, without a doubt. And you're going to see it more and more as he gets comfortable.''

The Eagles probably will keep four running backs. Pumphrey will be one of them, along with Blount, Darren Sproles, and either Wendell Smallwood or undrafted rookie Corey Clement.

Pumphrey brings the same kind of versatility to the offense that Sproles does. You can hand him the ball or throw it to him. You can line him up in the backfield, out wide, or in the slot.

"When he was here, we'd line up a lot in '21' personnel [two running backs, one tight end] and then motion him out into 'trips' or in the slot,'' Horton said. "Then he's on a 'backer or a safety. That's the kind of matchup you're looking for with a guy like that.''

Last season, Pederson seldom used "21'' personnel. The Eagles used it just six times in 1,080 offensive plays.

If their training-camp practices are any gauge, you're going to see "21'' a little bit more often this season.

"It's all about matchups in this league, and how you create mismatches with guys like Sproles or Pumphrey or [tight end Zach] Ertz or [tight end Trey] Burton and get them lined up against linebackers and different things,'' quarterback Carson Wentz said. "That's the name of the game.''

At San Diego State, Horton mostly gave Pumphrey the ball the old-fashioned way. Despite his size, he had an iron man workload, lugging the ball 658 times his last two seasons there. He never caught more than 27 passes in a season.

But he's a natural pass-catcher with soft hands. The Eagles drafted him with the idea of using him much the same way that Sproles has been used in his career.

"First of all, he catches the ball a lot better than I would've thought as a running back,'' Wentz said. "He's a playmaker. So it'll be good for him these last two weeks of preseason to go out there [and get a lot of playing time]. That'll be big for him.''