While Kirk Cousins was perfect throwing the ball Thursday night, the running game wasn't able to get going until the third quarter of the preseason opener.

Redskins head coach Jay Gruden is confident that the team's run game can complement a lethal passing attack this season.

That remains unchanged, even after Matt Jones managed to gain just one yard on two carries during Thursday night's preseason opener against the Atlanta Falcons.

And not until the third quarter did the yards on the ground start to come in bunches, as the Redskins had just 12 rushing yards on their first nine carries before finishing the evening with 79 yards on 24 carries.

"We are going to stick with it," Gruden said. "We are going to fix it. We have to get our line coming off better. We have to get it to the right people. Atlanta played very good defense. They loaded up the box and did a nice job stopping us. That is no excuse we have to run the ball better."

After Jones played in just the first series of the game, Chris Thompson and 2016 seventh-round pick Keith Marshall worked with Colt McCoy and the second-team offense, although neither running back was able to do much when the ball was placed in their hands.

Against Atlanta's third-team defense, though, rookie Robert Kelley and 2015 practice squad member Mack Brown sliced up the Falcons.

Kelley would finish the evening with a game-high 40 rushing yards on just seven carries. He also proved difficult to stop on the goal line, punching in his first preseason touchdown from a yard out.

Brown followed up Kelley with 28 rushing yards of his own.

The way both young players played impressed veteran tight end Niles Paul.

"I mean just seeing them out there playing relentless and trying to make a team, I'm proud of those guys," Paul said. "And the way they stepped up."

While Jones and Thompson each will have big roles on the offense this season, the team's third running back position appears, for now, to be up for grabs.

Kelley hopes that the impression he made will go a long way once the roster begins to be trimmed down.

"After this game, I felt more confident, like knowing I can play with those guys out there and the level, moving up from college to the NFL and the hitting isn't harder but there are better players," Kelley said. "I feel more confident, just being able to make plays with NFL guys, so I feel better about myself."

With three more preseason games – along with a handful of training camp practices – the backend of the unit should have more clarity before the Redskins take on the Pittsburgh Steelers in the regular season opener less than a month from now.

"They're all intriguing to me to be honest," Gruden said recently of the running backs. "We have position battles, running back is no different, but Matt Jones is doing an excellent job, Keith Marshall, he shows up every day and has a burst of speed you just don't see every day. Chris Thompson has been doing a good job. Robert Kelley, not many people knew who he was, but people know who he is around here, he's doing a great job. So it's interesting to watch these guys play."