Guzan hailed the influence of goalkeeping coach Gennoe, who he says has helped him "push on to the next level."
He told Villa's website: "The past few years have been really good.
"He's helped me push on to the next level and stay there, keep me fit and on my toes.
"It's important as a goalkeeper that you're constantly seeing balls in training that are game-like situations.
"That's what we recreate. And he does a fantastic job."