Redskins running back Adrian Peterson spoke to the media after his first practice with the team Tuesday. (Katherine Frey/The Washington Post)

Adrian Peterson didn’t join the Washington Redskins to simply blend in and help fill out a roster low on running backs. The future Hall of Famer said he has every intention of being the starter at the position when the team opens the regular season on the road against the Arizona Cardinals on Sept. 9.

“Without a doubt,” Peterson said. “And I would be cheating myself if that wasn’t my approach.”

All eyes were on Peterson as he made his practice debut with the Redskins on Tuesday. The seven-time Pro Bowl honoree and 2012 NFL MVP sported No. 26, and his sinewy 6-foot-1, 220-pound frame immediately stood out alongside the other healthy running backs — Rob Kelley, Chris Thompson, Kapri Bibbs and the newly signed De’Veon Smith.

The Redskins brought in Peterson, veteran free agents Jamaal Charles and Orleans Darkwa and others in recent days as they went through two practices with just three running backs available. Second-round draft pick Derrius Guice (torn anterior cruciate ligament) is out for the season, while both Samaje Perine (ankle) and Byron Marshall (sprained knee) are sidelined at the moment, creating a void at the position.

Charles visited Washington but didn’t work out. Peterson sent a message to the organization by going through a full session.

“The average guy that has accomplished what Adrian has accomplished probably would feel like, ‘I don’t have to work out,’” Redskins Senior Vice President of Player Personnel Doug Williams said. “But he didn’t come in with that attitude. I think it shows you the person he is, that he has humility and he realized that he wanted to play. He realized that he’s in a good situation as far as what we have here, the pieces to go with [him].

“He was willing to do whatever it takes to show us that he deserves an opportunity to be on this football team.”

The process started about two weeks ago, after Guice injured his knee Aug. 9, when Peterson’s agent reached out to the organization to express Peterson’s interest in joining the team. But that was before Perine and Marshall went down. Peterson was in Oklahoma on Sunday when his agent texted him. He was in Washington on Monday.

Coach Jay Gruden raved about the workout, and a one-year, $1.015 million contract sealed the deal. There is virtually no risk for the Redskins if things don’t pan out.

“He proved to us he’s in great physical condition,” Gruden said. “He’s actually a physical freak, if you want to say that. From the start of the workout … to the end of the workout, he didn’t even break a sweat hardly. He’s in great shape, explosive. And that’s what really sold us.

“Sometimes these backs come in for a workout and they haven’t been doing anything and you can tell they’re out of shape. Some of the backs we had in here, they were huffing and puffing, keeling over. He was standing straight up. He could have gone another two hours. So that played mostly into it: his great physical condition.”

Gruden said there are a lot of factors that will ultimately determine the team’s choices for its 53-man roster, including how many running backs the team will keep. Health will be one of the biggest influences, as Perine was working out on the side without pads at practice Tuesday and is expected to be back sooner than later. Marshall could be out for a more extended period of time. The plan is to have Peterson suited up Friday against the Denver Broncos in the third preseason game. Kelley is the No. 1 back who works early downs, while Chris Thompson is one of the most dynamic weapons on the roster as a third-down back.

There are concerns about how much Peterson has left in the tank as a 33-year-old who has dealt with injuries and seen a drop-off in his productivity the past few seasons. Gruden said he wants to evaluate Peterson in live action after a stinger cut Peterson’s time with the Cardinals short at the end of 2017.

“I’d like to see where he is,” Gruden said. “After contact. I want to see the explosion in the hole, his vision, all that good stuff. I don’t think he’s going to lose that. It’s just a matter of taking hits play after play after play and just seeing where he stands as far as stamina goes.

“You have a pretty good idea of what he’s good at based on his career. We have all those runs that he’s been successful with. It just makes your play-action game a little bit better and your play-action keeper bootleg game a little bit better. We’ll feel it out as we go on, but we understand the skill set that Adrian has and hopefully we’ll work to it.”

Peterson ran for 529 yards in 10 games last season, and his last standout season was a 1,485-yard, 11-touchdown effort with the Minnesota Vikings in 2015. He ranks 12th in league history with 12,276 career rushing yards but had a career-low 3.4 yards per carry average last year. Peterson, however, had something to say to those who believe he is finished.

“It shows me people don’t really know about football,” Peterson said. “I feel like people that know the game of football know different situations a player might be in. So when people go back and say, ‘Oh, [3.4] yards per carry,’ there’s a lot that contributes to that as well. I just brush it off. And I continue to work because at the end of the day I control my output.

“So that’s why I continue to work hard. I knew an opportunity would present itself. And at the end of the day, God’s willing, stay healthy, the guys up front stay healthy as well, I know that I’ll be able to contribute in a big way in the run game.”

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