One look at Raiders running back Latavius Murray, and it’s hard not to think of Adrian Peterson and DeMarco Murray. Yes, those are two of the best running backs in the NFL, and Latavius Murray has only 82 career carries.

But just look at him. How many running backs are 6-foot-3, with a chiseled 230 pounds and speed to burn?

“Size and speed,” said Murray, who was asked to switch to linebacker by his coaches at Central Florida. “Not many guys with that combination. I do watch those two guys, but I know I have to stick to my game.”

And — not putting the cart before the bell cow — he has to win a starting job.

Murray, who missed his rookie season in 2013 with a foot injury, had some highlight-reel runs last season and started the last three games. But new head coach Jack Del Rio still brought in Trent Richardson to compete with Murray for the starting job.

Well, Richardson has missed the first week of training camp with an injury, and Murray isn’t looking back.

He is getting all of the first-team reps and has looked powerful, especially in a scrimmage late in Wednesday afternoon’s practice in Napa.

“My mentality is to stay where I am at and be that guy,” Murray said. “It’s big being able to get a series of carries together and getting comfortable back there. Get used to the scheme and the guys I am in there with.”

Murray wasn’t able to prove that he was a starter to the head coaches last year, Dennis Allen and interim man Tony Sparano. It took 10 losses of Darren McFadden and Maurice Jones-Drew running into tacklers before Sparano finally threw his hands up and gave Murray a shot.

General manager Reggie McKenzie was asked what took so long, what was holding back Murray.

“I think he’s holding himself back,” McKenzie said. “Being able to practice all the time, not having nitpicking injuries. Last season, leading up to it, he was nicked up. So, if he could stay healthy, nothing is holding him back.”

This year the 2013 sixth-round pick is coming off the first offseason in which he was 100 percent healthy, and he was even a little faster, he says, coming into camp.

Is Murray ready to be a 1,000-yard, No. 1 running back in the NFL?

“No question,” McKenzie said. “He can do it all.”

Murray had the foot injury his rookie year and an ankle injury and concussion last year. He still finished with 75 carries for 413 yards (5.5 average) and two touchdowns, one a 90-yarder against Kansas City, in the final seven games.

“I had a great offseason, and I want that to carry over,” he said.

It started with renting a house in Newport Beach (Orange County) and working out with former Central Florida teammate and current Jacksonville quarterback Blake Bortles. From there, he went back home to New York and did whatever friend and trainer Vinny Scollo told him. Murray hit the weights, ran hills with a flak jacket and played dodge ball — with large, four-square balls being flung at him.

“The biggest improvement has been in his explosiveness and his conditioning,” Scollo told Syracuse.com. “Last year, we really had to taper the workouts and work around his injury. This year, his conditioning, his wind, is 100 percent there.”

Raiders offensive line coach Mike Tice had heard Murray was a hard worker. Tice, back in the day, played for longtime coach George O’Leary, who coached Murray at Central Florida.

“We talk about it a lot, like ‘That’s something O’Leary would do or say,’” Murray said. “It’s pretty cool. The O’Leary mentality is tough, physical. We still talk, and he knows I am in good hands with Coach Tice, and I know that as well.”

O’Leary said Murray had to learn to run between the tackles in college instead of trying to bounce everything outside. Instead of reading the defensive linemen, Murray learned to read the linebackers.

“George (said) he is a hard worker and a tough kid,” Tice said. “So I know Latavius was raised the right way, and I know he got yelled at a lot.”

Tice likes Murray’s jump-cut move and how he can change direction. But the main thing, again, is the combination of speed and power.

“For a big guy, Latavius has extremely good quickness,” Tice said. “And when he gets behind his pads, he is hard to tackle. Smaller linebackers might be in serious trouble.”

Vic Tafur is a San Francisco Chronicle staff writer. E-mail: vtafur@sfchronicle.com Twitter: @VicTafur