( dpa ) - Novak Djokovic on Friday withdrew from the ABN-AMRO World Tennis event due to influenza.
The new Australian Open champion has frequently suffered from fitness problems, and lost this week in the second round at Marseille.
The Serbian world number three was unable to play his opening singles at the Davis Cup last weekend against Russia and was beaten in his second match as he quit against Nikolay Davydenko.
Rafael Nadal is top seed at the indoor event as he plays for the first time since the Australian Open, where he lost a semi-final to Jo-Wilfried Tsonga.