Generally speaking, running backs either begin to decline or hit a wall around the time they turn 30.
That hasn't happened to Darren Sproles.
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In fact, today is Sproles' birthday. He turns 35 and after rehabbing his way back from a torn ACL and a broken forearm, he still hasn't shown signs of slowing down. That, in itself, is pretty incredible.
Since it's Sproles' birthday, it seems like a good time to look into the elite company he can join this year as a productive 35-plus-year-old in the NFL.
Sproles will enter the 2018 season with 19,155 all-purpose yards. He's already eighth in NFL history and has a chance to surpass quite a few names on this list with a productive season. There are just seven players in front of him and five of them are already Hall of Famers:
Jerry Rice: 23,546
Brian Mitchell: 23,330
Walter Payton: 21,803
Emmit Smith: 21,564
Tim Brown: 19,682
Marshall Faulk: 19,190
Steve Smith Jr.: 19,180
It's impossible to know just how productive Sproles will be in 2018, especially as he's coming off a significant knee injury. Last year, he had only two healthy games and he had just 88 all-purpose yards in them, putting him on pace for 704. That would have been significantly lower than his three previous seasons with the Eagles.
In those three previous seasons, we saw a very slight decline from 1,237 in 2014 to 1,171 in 2015 to 1,108 in 2016.
But if Sproles can return to form and is able to eclipse 1,000 all-purpose yards in 2018, he'd become just the eighth running back in NFL history to do it at age 35 or older. A search of Pro Football Reference shows the top mark ever for a running back over 35 (must be 35 or older on Dec. 31 of that year) was Herschel Walker's season in 1997 (1,336).
If Sproles eclipses that 1,000-yard mark, he'd also become just the second Eagles player (any position) to do it at 35 or older. The only other Eagle to do it was Irving Fryar, who had 1,316 back in 1997 too.
He'd also move past Smith, Faulk and Brown into fifth all-time in all-purpose yards, becoming just the fifth player in NFL history to surpass the 20,000-yard mark.
Even in 2016, when he had a down year as a punt returner, Sproles still had 224 punt return yards. If he surpasses the 200-yard mark this season, he'd be just the third player in NFL history to do it at 35 or older. The other three are Michael Lewis (336 in 2007), Leo Lewis (225 in 1991) and Mel Gray (205 in 1996).
And this year, with the new kickoff rules, there's a chance the Eagles might use him as a kick returner too. More chances to pile up yards.
The man himself doesn't care too much about individual achievements; he'd rather win another Super Bowl. But that doesn't mean we can't enjoy tracking his progress.