And how rewarding it must be for the former Fresno State star.
Injuries kept Mathews out of four games as a rookie. In 2011, he missed only two games despite a multitude of tweaks, averaged 4.9 yards per carry and totaled more than 1,500 yards from scrimmage.
But the injury bug migrated back last year, as he played in only 12 games, and mustered a 3.8 yards-per-carry average on 184 attempts.
Mathews has voyaged through all 14 games of the 2013 season relatively unscathed.
He's already tallied a career-high in carries (236), which is huge for a supposedly "injury-prone" running back. While he may fall short of the numbers he accumulated in his second professional campaign, playing in all 16 games would be a major achievement for the Chargers running back.
But the NFL isn't giving out participation awards, and Mathews shouldn't receive an exorbitant amount of praise for avoiding the IR list this year.
Then again, he deserves to be commended for his production.
Mathews is currently one of seven backs who've eclipsed the 1,000-yard plateau, a group which could increase to nine or 10 backs at the conclusion of Week 15.
No, he hasn't been an elite runner capable of carrying his team in Adrian Peterson-type fashion.
Yet, Mathews has morphed into the reliable, unquestioned feature back the Chargers hoped they were getting when the drafted him No. 12 overall in 2010.
With a high-volume, borderline elite quarterback like Philip Rivers running the show, San Diego needs a dependable running back to complement a pass-first offense and keep defenses honest.
Mathews has done that.
Rivers will probably finish in the top 10 in terms of pass attempts in 2013.
However, Mathews has been given at least 15 carries in eight games in his fourth year, the most in any single season in his career.
Maybe most importantly, he toted the rock 29 times in each of the last two games for his previously 5-7 team, essentially must-win contests.
In Week 14 against the New York Giants at home, Mathews banged out 103 yards and a touchdown on the ground in victory. He also caught three passes for 32 yards.
On Thursday Night Football in Denver in Week 15, Mathews totaled 127 rushing yards on his 29 attempts and scored the touchdown in the third quarter that gave the Chargers the lead for good.
At 7-7, the Chargers find themselves in the thick of the AFC wild-card hunt. With home games against the Oakland Raiders and Kansas City Chiefs remaining on the schedule, Mike McCoy's team could sneak into the playoffs, maybe even at 8-8.
A year ago, not many would have believed that San Diego would ever be able to lean on Ryan Mathews in critical, season-defining moments.
But, in 2013, the San Diego Chargers running back, who's suffered through an assortment of nagging and serious injuries, has proven to be a powerful and dynamic workhorse the Chargers.