Darren Sproles has been piling up yardage since he first picked up a football in a Pop Warner game at the age of nine. That’s when he sprinted 80 yards for a touchdown. The San Diego Chargers running back/kick returner hasn’t let up since. While at Kansas State, Sproles set 23 school records and had the sixth-most all-purpose yards in NCAA history. This season, in Week 6 against Denver, he set the Chargers’ all-time record for combined yards on kickoff and punt returns with 5,262. That’s the game in which Sproles returned a punt 77 yards for a touchdown. Sproles, drafted in the fourth round by the Chargers in 2005, is a speedy, shifty runner who is dangerous out of the backfield or as a receiver. At 5-feet, 6-inches and185 pounds, Sproles also is one of the NFL’s smallest players. But that doesn’t stop him from making big plays. In the season opener at Oakland, Sproles returned a kickoff 59 yards to set up a field goal and his 5-yard run with 18 seconds left gave the Chargers a 24-20 win. Against Baltimore the following week, Sproles caught seven passes for a career-high 124 yards, including an 81-yard TD reception. He had a 58-yard scoring catch in a 37-7 victory at Kansas City in Week 7, and his 21-yard catch in Week 9 at New York set up the game-winning touchdown in a 21-20 decision over the Giants. And there is something about playing the Indianapolis Colts that gets Sproles going. In a 2007 game against the Colts, Sproles became the ninth player to return a punt and kickoff for touchdowns in the same game, his first two NFL TDs. In last season’s playoff game at Indianapolis, Sproles’ 22-yard scoring run in overtime gave the Chargers a 23-21 win. He had 328 all-purpose yards in the contest, the third-most in postseason history. Sproles has been LaDainian Tomlinson’s backup since Michael Turner left for Atlanta after the 2007 season. And with Tomlinson’s production slipping over the past couple of years, it might be time for Sproles to start. That’s probably what the Chargers were thinking when they kept Sproles from testing the free-agent waters by tagging him as their franchise player after last season.