“Whether (Mathews) could’ve or couldn’t have returned, I wasn’t comfortable having him return,” Chargers head coach Norv Turner said. “Depending on the severity of it, I don’t want an injury that might be a one-week injury turn into a six-week injury. I thought Mike Tolbert stepped in there and played awfully well (and) obviously we had some plays from Darren (Sproles). We have depth in that position.”
Seems like the injury isn't all that serious, which is good news for owners. It also seems Mike Tolbert may have some value going forward over Darren Sproles as Mathews handcuff.
The article also talked about concern over Mathews having another fumble in the gam, but Turner said "Ryan is not a fumbler."