San Francisco ranks fifth overall on defense. A unit that went on the road last week to New York and shut out a Jets team that blew out the Bills in the season opener.

"That was an impressive game," said Bills quarterback Ryan Fitzpatrick. "I watched the defensive film, obviously. The way that they were flying around, hitting people, taking away the run game and not giving any big plays in the pass game. It was definitely a statement game for them."

"They are fast, they are aggressive," said Bills wide receiver Stevie Johnson. "They’re not too complicated as far as mixing things up with blitzes and all that. They are pretty confident in their schemes and stuff, but they don’t make too many mistakes."