Dutchman Van der Sar admits it was much easier for him to establish himself in the Manchester United goalkeeping spotlight than it has been for the young Spaniard.
He said: "I adapted right away at United but I was 34 and I had already played for four years in England at Fulham.
"You get used to the pace of the game in England - the crosses that come in, the corners and the crowds.
"But I think De Gea is progressing. He had a fairly hard first year but he is getting used to that pace and showing the ability that made Sir Alex Ferguson sign him.
"That is fantastic for the club and himself, of course. He makes a lot of saves with his feet - but so did I.
"I wouldn't have done that one in Madrid against Real in the Champions League, that was a strange save.
"But, in general, it doesn't matter how you keep them out, as long as you do stop them."