AP

There’s little argument to be made against the assertion that Chargers running back Ryan Mathews has been a disappointment in the three years since he was selected with the 12th overall pick.

Mathews has battled a variety of injuries in his first three seasons and showed an alarming inability to hold onto the ball while healthy, leading the team to give him a seat on the bench in favor of Jackie Battle last season and raising all sorts of questions about his long-term outlook in San Diego. Mathews knows that he has failed to live up to expectations and doesn’t do much to sugarcoat the shortcomings.

“So far, what I’ve done right now. I’ve been just an average back,” Mathews said, via Kevin Acee of U-T San Diego. “I got a lot of people just frustrated with my performance in the last few years. They expected me to come in and do big things. And I expect myself to.”

Mathews also admitted that he’s struggled with being the successor to LaDainian Tomlinson in the Chargers backfield. Tomlinson set a very high standard during his years in San Diego, one that has weighed on Mathews during his first three years with the team.

“I put a lot of pressure on myself to fill LT’s shoes,” Mathews said. “I was trying to live up to those expectations — what he was doing in his prime, all the yards he’s getting, all the touchdowns he’s getting, just trying to live up to that. I knew I was the first-round pick, [the Chargers] moved up [16] spots and all that, and I was just trying to do more than what I should have been doing. I think I took all the fun out of it and stressed myself out over it.”

If that’s the case, Mathews must have been happy to hear that Tomlinson rebuffed a casual approach from the Chargers about returning for the 2013 season. It’s a reminder that as much as the new regime has expressed confidence in Mathews, they aren’t closed to exploring other avenues to find the kind of production in the running game that Mathews has failed to provide thus far.

That makes 2013 a big year for the former first-rounder and no explanations of ghosts over the shoulder or bad injury luck will carry much weight in the event Mathews remains just an average back.