He points to his fellow Holland international Wesley Sneijder as one man who could be key.
"Yes, he's a great player and we're still very good friends," Van der Vaart told the club's website.
"He's a player we have to contain because he's their inspiration in midfield.
"True they have many good players but we have to make them worry about us and ensure that this game is dictated by what we do.
"We showed Inter what we're about in the second half at the San Siro - now we have to believe that we can do it again."