By ESPNSTAR.com staff
Hamburg are currently 9th in the league after picking up just 13 points from their opening ten games, and fell to their fifth defeat of the campaign last weekend when they were beaten by Bayern Munich 3-0.
Van der Vaart returned to the Imtech Arena earlier in the summer following two successful years with Barclays Premier League outfit Tottenham, but has so far failed to deliver the same performances he did in his last spell in the Bundesliga, something he admits he is looking to address.
"I have a higher standard for myself and would like to meet it," he told Bild.
"I cannot and will not be satisfied with the performances that I have shown so far. I need to get better."
The Netherlands international also believes the entire Hamburg squad can further lift their game, and is hoping their rise will start this weekend when they take on Freiburg.
"The team and I have to turn things up a notch," Van der Vaart added.
"Ideally, we start doing so on Sunday evening against Freiburg."
Hamburg narrowly avoided relegation last season after finishing 15th in the league, five points away from the drop zone.