ASHBURN, Va. (AP) When Robert Kelley showed up a few pounds heavier after his red shirt year at Tulane, running backs coach David Johnson gave him a backpack with ''Fat Rob'' inscribed on it, and the nickname stuck.
More of a moniker among friends than anything else for several years, ''Fat Rob'' resurfaced when Kelley joined the Washington Redskins in training camp. The undrafted free agent is now going into his third game as the Redskins' starting running back Sunday night against the Green Bay Packers.
He earned the spot by being Positive Rob.
Usurping Matt Jones as the No. 1 back, Kelley has stabilized the offense by holding onto the ball and seemingly always getting back to the line of scrimmage if not much further.
''There aren't many negative plays with Robert,'' coach Jay Gruden said. ''You stay on track as a play-caller, and it makes the game flow a lot smoother when you're in second-and-7, second-and-6, second-and-5, and that's a great tribute to him. He's a hard runner.''
Kelley isn't flashy, but he's effective. Since taking over the starting role Oct. 30 against the Cincinnati Bengals, 39 of his 43 carries have been for positive yardage, with just one loss and three for no gain.
Kelley takes great pride in that stat.
''That's how I run the ball,'' Kelley said. ''I'm not one of (those) guys that sits back all day and just try to dance around. I try to get north and south as much as possible.''
Gruden said Kelley putting the Redskins in manageable down-and-distance situations means ''your whole playbook is open'' and allows quarterback Kirk Cousins to freeze defenders with play-action. It worked in a 26-20 victory over the Minnesota Vikings when Kelley ran for 97 yards.
''It does make a difference and keeps our offense going in a positive direction,'' Cousins said. ''The play-action game can be effective for us.''
Because third-down back Chris Thompson is a capable receiver out of the backfield and the change-of-pace runner, Kelley doesn't have to try to do too much - just hold on to the ball. While Jones lost the job in part because of his fumbling problems, Kelley has yet to fumble in 60 NFL carries.
Success has come quick for the 24-year-old from New Orleans, so much that he doesn't believe it. When Jones hurt his shoulder during the preseason, Kelley was reluctant to say if he'd be able to carry the load as the starter.
When Kelley learned from Gruden last month that he was being named the starter, he tempered his excitement and was determined to make the coaching staff proud. He's in the midst of doing just that, but he didn't expect to be a pro starter this quickly.
''I'm always surprised,'' he said. ''I always try to take advantage and don't just go out there and get big-headed and stuff like that.''
Far from becoming over confident, Kelley continues to study film in the hopes of improving. He saw cuts he missed against the Bengals and worked to not make the same mistakes in his second start.
He said some of his biggest runs have come on ''off-schedule'' plays, but he hasn't yet broken off anything longer than 18 yards. Kelley considers cohesion with the offensive line the next step in his progression.
''Just keep constantly showing my guys I trust in them - the front line, the front five - and make those guys look better,'' Kelley said. ''They also try to make me look better. They make holes for me that I don't have to do too much to get through and stuff like that. We kind of work together and try to build that chemistry with those guys.''
NOTE: WR DeSean Jackson was a limited participant in practice Wednesday because of a left shoulder injury. After missing the Vikings game he took part in individual workouts, but Gruden was noncommittal about Jackson's status for Sunday night.
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