"I know what I can do," McGahee added.
But the Chargers are tops in the NFL against the run, allowing just 79.6 yards per game. And they are out to prove they can stop McGahee.
"(McGahee) is a quality running back, don't get me wrong. He is quick, he runs out more on the outside. He's a quality player, and we're glad we have a challenge this week."
The challenge would be getting Williams his due. Despite being in the middle of a stingy run defense, Williams flies under the radar.
"I don't think he gets much notoriety because he is not one of those hoopla guys," defensive tackle DeQuincy Scott said. "He does his job, and that's good enough for him."
"It's unfair," Luis Castillo began, "he was never a guy you really heard too much about. You hear about Sam Adams and Casey Hampton of the Steelers and all those other guys. But you see what (Williams) does, the way he manipulates an offense and the way he makes offenses play around him. He changes the game."
Stopping the "best running back in the game" ought to bring Williams to the forefront – or perhaps it will simply be ruled that McGahee was in over his head when he made the declaration.