SYDNEY: World number one Roger Federer will not play in this week's Kooyong Classic in Melbourne, preferring to practise ahead of next week's Australian Open, tournament officials said on Monday.

Tournament Director Colin Stubs said he had been holding the eighth and final spot in the eight-player exhibition event open for Federer, but the Swiss opted not to take up his place in the draw.

Stubs said Federer's manager, Tony Godsick, contacted him early Monday to say that the 15-time Grand Slam champion would not take up the option of eighth spot in the field.

Federer, who is bidding for his fourth Australian Open, was defeated by Russian Nikolay Davydenko in the semi-finals at the Qatar Open last week before heading to Melbourne.

Federer is scheduled to have a hit on the Australian Open's Rod Laver Arena on Tuesday.

American Andy Roddick also opted not to play in the round-robin event after reaching Sunday's ATP final in Brisbane.

Stubs is expected to announce the eighth and final place for the Kooyong Classic at the players' media conference on Tuesday.

The Kooyong field contains six of the ATP's top 11 players including Argentinian Juan Martin Del Potro, who beat Federer in last year's US Open final.

Also featured are 2008 Australian Open champion Novak Djokovic, 2009 French Open finalist Robin Soderling, Australian Open finalists Fernando Gonzalez (2007) and Jo-Wilfried Tsonga (2008), Fernando Verdasco and Tommy Haas.