Talks between the player and Bundesliga outfit have taken place, with a loan or permanent exit from Tottenham an option as Rafael van der Vaart's future remains unclear.
The Bundesliga side is looking into options to replace Rafael van der Vaart, who has been linked with a possible reunion with Harry Redknapp at QPR as well as a move to Turkey.
Holtby is Hamburg's No.1 transfer target and Goal understands discussions have taken place between the player and the club's new chief executive Dietmar Beiersdorfer, with either a loan or permanent deal an option.
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The 23-year-old spent the second half of last season on loan at Fulham after falling out of favor under both Andre Villas-Boas and Tim Sherwood and has been afforded just one substitute appearance under new boss Mauricio Pochettino this term.
Cristian Eriksen, Erik Lamela and Nacer Chadli are currently ahead of Holtby in the White Hart Lane pecking order and he was an unused substitute as Tottenham ran out a comfortable 4-0 winner over QPR on Sunday, while his three teammates all impressed.
The former Germany Under-21 captain has struggled to make an impact in north London since his 1.9 million euro move in Jan. 2013 and could be keen on a return to the Bundesliga, while Spurs are thought to be open to selling him as Pochettino shuffles his squad.
Van der Vaart, who left Spurs for Hamburg in 2012 and has just one year remaining on his contract, is reportedly been courted by Trabzonspor ahead of the close of the transfer window next week.