They call it the Pony set. It's an apt name.
It's the moniker of the Eagles' two-running back formation when 5-foot-8, 176-pound rookie Donnel Pumphrey and 5-foot-6, 190-pound veteran Darren Sproles share a backfield.
Complete coverage of the Philadelphia Eagles and their NFL rivals from NBC Sports Philadelphia.
"It creates a lot of mismatches because we have great wideouts on the field as well as Carson Wentz back there," Pumphrey said.
"With both of us back there, we can just do crossing patterns and keep the linebackers all mixed up. Even when we motion out, it's going to most likely be a linebacker on us and it's a mismatch on its own."
The Pumphrey-Sproles comparisons are unavoidable, yet understandable. While the two don't have identical body types, they're both small and it seems like Pumphrey will have a Sproles-like role with the Eagles.
Sproles, 33, previously has talked about retiring after the 2017 season, so the fourth-round pick could be his heir apparent. Pumphrey has also been working on returning kicks and punts during OTAs, something he didn't do much of in game action in college - and he's looked comfortable doing it. It's yet another thing he can learn from Sproles.
"It's honestly been unbelievable to play under his wing, learn different stuff, different aspects of the game with him," Pumphrey said.
As the current round of OTAs began in the rain on Tuesday, the Pony set was scratched momentarily because Sproles was away for a family matter. It will return, but in the meantime, the Eagles have been showing the various ways they plan on using their new versatile weapon.
That means, in addition to his duties as a running back, Pumphrey will be used out of the backfield as a receiver and in the slot. On Tuesday, the Eagles stacked him as the back end in a bunch formation, almost hiding him behind bigger receivers.
"Pump is so laterally quick," Ertz said. "You see it out there. His change of direction is incredible. Obviously, the coaches are going to have unbelievable pieces to use in this offense between him, Sproles, myself, we added guys like Alshon (Jeffery) and Torrey (Smith). Hopefully the middle of the field will be a little more spaced out than in years past. So we're excited to use him in different ways.
"I mean, you put Sproles and him on the field, how is a defense going to match up? Are they going to play base, will they play dime? Sproles has obviously shown he can run between the tackles, we'll see how much Pump can do in the run game. I think guys are excited to see especially when the pads go on, live bullets, to see that lateral quickness."
Ertz said the Pony set will create problems for defenses similar to those occurring when he and Trey Burton come out in the Eagles' two-tight-end set. Which defense will teams choose to use?
And then Ertz questioned what teams would do if the Eagles come out with 176-pound Pumphrey next to 250-pound LeGarrette Blount in the same backfield.
"We've got a lot of chess pieces, so it's up to Doug (Pederson) and Frank (Reich) and [QB coach John DeFilippo] to kind of make the most of this," Ertz said. "But that's the good thing, they've shown they can do it in the past and we trust them as offensive players that they'll put us in situations to be successful."