Hamburg sporting director Frank Arnesen is waiting for a signal from Tottenham forward Rafael van der Vaart before getting serious with his interest.
Van der Vaart has been linked with a move away from White Hart Lane this summer, with new boss Andre Villas-Boas reportedly willing to listen to offers.
And the Netherlands international did nothing to dampen the speculation when he said last month: "I am pleased... I am still causing interest at Hamburg."
Van der Vaart played for the Bundesliga club between 2005 and 2008.
However, Arnesen is still holding out for something a little stronger from the 29-year-old, who joined Tottenham in 2010 from Real Madrid.
"I can only say that he is a great player and one that knows Hamburg very well," Arnesen told Welt. "I don't want to talk about it too much because Van der Vaart has a contract at Tottenham Hotspur until 2015.
"If I get a signal from his end that there might be something, things will be different. At the moment it is not practical. He is on holiday after the European Championship. In the next few weeks we will see what happens."