Kelly might say "big people beat up little people," but that's only if the big person can catch the little person. And Sproles, who is the second-shortest player in the NFL, was appealing to Kelly as another player who would keep defensive coordinators awake at night. Kelly guessed the Eagles saw more man-to-man coverage than any other team in the NFL last season, and his goal this offseason was to find ways to exploit that coverage.
"When you put Sproles in that role of coming out of the backfield on linebackers, you need help somewhere," Davis said. "He's such a receiving threat and an open-field threat. You put him in the box between the tackles, OK. You put him in space against some of our defensive backs? That man is tough."
And it's not just defensive coordinators who must account for him. Eagles special-teams coordinator Dave Fipp can still detail Sproles' 39-yard, fourth-quarter kickoff return that helped the Saints win the playoff game. Several Eagles have approached Sproles in the last few months to rehash that play.
There is still intrigue about how exactly Sproles, 31, will be used - the first training camp practice is on Saturday, and the first preseason game is Aug. 8 - but of late the team has emphasized that Sproles is a running back.
Despite Sproles' skills as a receiver out of the backfield and as a returner, Kelly corrected a questioner this spring who put Sproles among the pass catchers. In a June conversation, Sproles was resolute that "I'm a running back" and that finishing three of the last four seasons with more receptions than carries was a function of the offense, not his talent.
"There's no doubt that Darren is a running back," running backs coach Duce Staley said. "Darren, his quickness is unbelievable. . . . I've seen him make some cuts in OTAs, like, wow, this guy looks like a rookie. He's able to put his foot in the ground and can get upfield. I already have one that can do that. To have two is a blessing."
The other player Staley referred to was LeSean McCoy, the NFL's top rusher who will monopolize the Eagles' carries. The two running backs behind McCoy on the depth chart last year carried the ball only 86 times, so there are fewer carries to dispense if the Eagles want to use Sproles as a rusher and still provide McCoy a comparable number of touches to last year's 314.
"The main thing is I want to keep him fresh, give him a spell every now and then," Sproles said.
Helping Sproles is that he's different from the other running backs on the team - and almost every other player, too. Sproles insists his height works to his advantage. By the time defenses locate him, Sproles already has built up his speed. And because of his quick feet and low center of gravity, he can be more difficult to bring down.
"When a line raises up, [defenses] can't see me until the last minute," Sproles said. "Linebackers are really guessing where I'm going to be at."
What has stuck out to Kelly is the way Sproles practices. When Kelly was on the pro-day circuit, he chatted with Vikings offensive coordinator Norv Turner, who coached Sproles in San Diego.
"You'll have to slow him down because he only knows one speed," Turner told Kelly.
That's what Kelly has seen so far. He also said Sproles has value in the meeting rooms, where Sproles' experience (he is five years older than any other running back on the roster) shows.
That experience has a downside. Running backs usually don't age well. Sproles' 2,696 all-purpose yards in 2011 set an NFL single-season record, but those numbers declined the last two seasons, and Sproles' 1,273 all-purpose yards in 2013 were the fewest in his eight-year career. Part of that had to do with a reduction in kick-return yards - a rule change in 2012 resulted in more touchbacks and the Saints split kick-return duties last year - but Sproles' offensive production also declined.
The Saints also were motivated to move on from Sproles, allocating his salary space elsewhere. That's not often a promising sign.
But Sproles believes he's an exception because of the way he plays, which would allow him to play longer. He does not take big hits because his game is often played in open space instead of in congestion. Plus, he bloomed late - his load only intensified in his fourth season in the league, and he hit his stride with the Saints during the last three seasons.
"When I really did start playing, they used me in spurts, I really didn't have to pound the ball like that," Sproles said. "Maybe a couple games, but not my whole career."
Sproles missed one game last season because of an ankle injury, three games in 2012 because of a hand injury, and was sidelined the entire 2006 season because of an ankle injury. But he has held up well for most of his career, and the Eagles are encouraged there are more productive seasons awaiting him in Philadelphia.
"I see the way Chip runs his offense," Sproles said, "and the places he can put me in."
Darren Sproles has been a versatile threat in the NFL during the last six seasons, although his numbers have declined the last two years. The NFL's kickoff rules and fewer kickoff returns affected those statistics, and the Eagles are counting on Sproles to fill a big role in 2014. Here is Sproles' production in yards, by category, over those six seasons:
Year Rush Rec PR KR All-purpose Rank
2008 330 342 249 1,376 2,297 2
2009 343 497 183 1,300 2,323 5
2010 267 520 166 1,257 2,210 3
2011 603 710 294 1,089 2,696 1
2012 244 667 183 483 1,577 17
2013 220 604 194 255 1,273 35