SAN DIEGO -- Let’s do it again.

San Diego Chargers running back Ryan Mathews likely has that familiar refrain from the popular song by the Staples Singers in his thoughts when contemplating his performance last season.

In 2013, Mathews finished with a career-best 1,255 yards on a career-high 285 rushing attempts, averaging 4.4 yards per carry. He rushed for more than 100 yards six times, second to Philadelphia’s LeSean McCoy. The Chargers finished 5-1 in those games.

But the Fresno State product wants to take it a step further in 2014. Because of a severely sprained ankle suffered against Oakland toward the end of the 2013 season, Mathews was ineffective in the playoffs, rushing for a total of 78 yards in two contests against Cincinnati and Denver.

Although he played a full 16-game season for the first time in his four-year NFL career, Mathews is focused on being on the field and at his best when the games matter most -- the playoffs.

“It was hard, not being able to finish the year out,” Mathews said. “Sixteen games is 16 games. I played a full season, but I didn’t really get to contribute in the games after the season -- the real games when it really counts.

“That’s my expectation this season. I’ve got to do more and do better, so I can be there with my guys to be able to help them out as much as I can when we get there again.”

To that end, Mathews went to work this offseason. He did running and agility drills at the beach to strengthen the smaller muscles in his legs and maintain his chiseled 220-pound frame.

“I think Ryan is going to have a great year, probably better than last year,” Chargers offensive tackle D.J. Fluker said. “He looks faster.”

Mathews played with a hop in his step and looked healthy during San Diego’s minicamp. At 26 years old, he’s more comfortable with his role on this team. Mathews is no longer burdened with trying to live up to the impossible expectations as this team’s first-round selection in the 2010 draft, set by the person who held onto the job before him, future Hall of Famer LaDainian Tomlinson.

Mathews smiles more. He wore rainbow-colored Under Armour cleats he said were named after Superman and the Incredible Hulk during offseason workouts at Chargers Park.

“I feel good,” Mathews said. “I feel honored just being able to be out here with my teammates, going through the plays and everything, just getting acclimated to football conditioning and football training. I’m just having fun. I feel great.”

But Mathews also will have some company in the backfield, with the Chargers signing running back Donald Brown during free agency to a three-year, $10.4 million deal. Brown is expected to serve as a complementary back to Mathews and talented third-down back Danny Woodhead.

With Mathews and Woodhead both entering a contract year, Brown provides some protection for the Chargers should they lose either player in free agency. Brown will make $4 million in total compensation in 2014, twice as much as Mathews’ $1.978 million.

Still, new offensive coordinator Frank Reich maintains that Mathews will once again serve as San Diego’s workhorse running back. That approach makes sense. The Chargers finished 9-2 last season when they rushed for at least 112 yards as a team.

“Ryan is as tough as a runner as I’ve been around,” Reich said. “He’s just a physically dominating runner. And he brings a physical presence to the game, which we love. The offensive line senses it, and they love blocking for him because of his physicality.

“He’s just a tough guy. There were times last season where I knew he was hurt, but he was just not coming out of the game. So he’s a tough guy, and a physically dominant runner.”

Mathews says he has to make the most of his opportunities when he’s on the field.

“Everybody wants the ball,” Mathews said. “If you’re a running back, you want the ball. But there’s only one ball in the game, so we all got to take turns. And when we’re in there, we have to do our best with it.

“We’re all competing against each other every day. We’re always striving to make each other better, and really to get the best out of one another. Just being able to have three different backs do three different things with our three different running styles is great. You can use us for anything.”