Van der Vaart has backed Adler to prove that the last result was an off-day, and says that he will perform against Greuther Furth.
"Rene is safer than any bank," Bundesliga.de quotes the Dutchman as saying. "I would trust him with my child and my bank account.
"I've played with many top goalkeepers in my career and I can guarantee that all of them have had an off-day. "I still say that Adler is world class and will prove it against Furth."
Van der Vaart has scored three goals in 17 appearances for Hamburg this season.