Were you surprised about this one? I wouldn't be.
Just because you're noted as the "starter," doesn't mean that you get the most playing time. Mathews has shown his elusive talent and is having a completely better year than his rookie season. He is 10th in the league in rushing yards. That includes him having his bye week and a couple of injuries.
When the Chargers get into their oppenent's territory, Ryan Mathews is being substituted for Mike Tolbert. I can see Tolbert playing on the goal line, but from the twenty, really? Tolbert is prone to fumbling the football, and Ryan Mathews has proven he can fight for extra yards. Every big run Mike Tolbert has, Ryan Mathews can do as well. He's just not getting the opportunity to do so.
Let's think back. When the Chargers had LaDainian Tomlinson and Michael Turner, they weren't splitting the carries 50/50. Why should Ryan Mathews have to do that now? I'm not saying that he's as good as LT, but he has the potential to become like him, if only he's given the chance.
This is pretty much an overstated subject. Analysts, Chargers fans and fantasy owners of Mathews will agree that he should be the every down back, and Norv Turner should allow him to develop in San Diego.