Guzan joined Villa in July 2008 from American side Chivas and had to bide his time behind both Brad Friedel and then Shay Given before being given his stripes.
"Brad has been exceptional for the club, really fantastic on and off the pitch," Lambert added.
"He's always bubbly around the place and a really solid character. He's a good guy as well which is really important. Overall, he's a credit to the club."