Villa admits he's a fan of Yamal after his past 12 months with Barca.
He told AS: "He's an incredible guy. The way he plays, the way he understands football... it's true that I don't know him personally, but I've been there a couple of times and he seems very calm and focused.
"This isn't an explosion of a footballer that will only last a few months. He's been proving his worth for a while now and, on the contrary, he continues to grow. He's really good and every time you see him play, he improves. Plus, he knows what it means to be a champion."
But on comparisons with Messi, Yamal also said: "Never. I think it's difficult to compare any player to Messi today. Lamine Yamal is already a world star. He's achieved important things in two years and, as a Barça fan, he excites me again.
"And the fans also have the right to dream with him, but I don't think it's necessary to compare him to Messi, because he will have a fantastic career."