He was originally given the lowdown on the 21-year-old from his USA colleague Michael Parkhurst, who played with Okore at Nordsjaelland.
Guzan told Villa's website: "Jores has been fantastic.
"For him to come on at Chelsea at that point in the game and perform like he did was tremendous.
"To then make his home debut in front of a packed crowd at Liverpool shows he's not intimidated by anything.
"Overall he's been fantastic and I see him improving all the time in training.
"He's getting more and more used to the Barclays Premier League and that will stand him in good stead. He will only get better.
"When he's out there on the pitch, he's got everything you need - he's quick, he defends strongly, he's very good technically, he's powerful - in fact he's as hard as nails.
"Off the pitch, you couldn't wish to meet a nicer person. He's a really good lad, very kind, quiet and down-to-earth."
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