Van der Sar said: “Cristiano is getting better and better. He is still only young but he is more mature now as a footballer.
“He has loads of qualities with the ball but is more aware now in terms of his positional play, the runs he can make, the other players who make runs for him, and of creating space for other players.
“I think it is his most productive season so far. He is scoring more goals and delivering more crosses. He has been excellent for us.”
He added: “I wasn’t in England after what happened with Cristiano at the World Cup but I can imagine what the papers and TV were saying.
“It was a country versus country situation and you do the best for your own country.
“The United fans have stuck with Cristiano and I think the opposing fans see the quality he has and the joy with which he plays the game.
“He will get some occasional booing but that’s all right. I thank that only serves to drive Cristiano onto even higher ground, to greater heights.
“Cristiano hasn’t let what happened and the reaction affect him at all. He is a very strong guy and has shown that this season.”