Watching him early on with the Chargers last season, I thought that he was out of gas.
But man...once he opened up the can against the Raiders in Week 4, Mack was lights out from then on out - especially since the Chargers were exactly playing with huge leads in the 4th quarter.
Wouldn't be mad at a one-year deal for him...but I suspect that it might take two just to be respectful.