Despite being made captain of his side, the Dutchman is under no illusions about his current poor form
The club have struggled in recent games losing their last three on the bounce, including a 9-2 hammering to Bayern Munich in that time.
And van der Vaart admits it is not only the team that is struggling for form just now but himself, too
“I’m playing badly at the moment,” the 30-year-old told Bild.
“The only thing I can do is fight and I'll do that. I know that we have better chances of winning if I am in good shape.”
The former Real Madrid and Tottenham Hotspur man was handed the armband after Heiko Westermann was relieved of his duties as club captain, and the Dutch playmaker insists there is no bad blood between the two players.
“This is a great honour and it’s still very special to me," he continued.
"The decision came as a surprise to me. To be captain again was not my goal … Heiko and I have a good relationship. He already told me in the summer that it's easy to imagine that I will be his successor.”
The Rothosen are 11th in the Bundesliga and find themselves four points off a European spot, and the Dutchman is confident that coach Thorsten Fink can steer the club in the right direction.
He added: “He does an outstanding job here and we all stand behind him. Hopefully he will remain our coach for a long time. Now we have to pay back his commitment through our performances."
Hamburg’s next game is away at Mainz on April 13.