Yamal responded to criticism from Van der Vaart with a goal in Spain's draw with Holland on Sunday. He later took to social media after the penalty shootout win to hit back at the Dutchman.
In response this morning, Van der Vaart said of the Barcelona starlet: "This goal was really of a great category. A world class goal, like the player.
"Still, I would advise him not to worry so much about a former player who is too fat and says something about him.
"It's something that really doesn't matter."
Van der Vaart had been highly critical of Yamal after the first-leg of this Nations League playoff.
"It seemed that Yamal did not like facing Jorrel Hato," he said. "These are things that I look at: I see details that start to bother me a little. Slightly lowered pants, not trying too hard, gestures a little superficial ...
"If you are so young, you should be happy for every minute you play with Spain. It doesn't matter how good you are: at that age, you have to prove it every minute and in every game. But that does not change the fact that Hato simply had him in his pocket."