Clark, in action for the Republic of Ireland against Uruguay on Tuesday, has been one of few bright spots for Villa this season.
"He is one of the best defenders I have played with. He is superb," said Cuellar.
"He is young but he has some amazing assets. He is quick, he has good technique, he can play, he can tackle and he's good in the air. He's got everything you need to succeed and flourish.
"He is also incredibly versatile. He will be one of the best defenders in the Premier League and in Europe too in my opinion. He's that good."
Source: PA
Source: PA