Australian Open [Images] champion Marat Safin's [Images] preparations for the defence of his title have taken a blow with the Russian's withdrawal from the Hopman Cup in Perth due to a long-standing knee injury.

Safin, who had been scheduled to partner Svetlana Kuznetsova [Images] in the mixed-team event, said he would prefer to concentrate on getting his knee right for the defence of his title at Melbourne Park, starting on January 16.

"Regrettably we have to announce that Marat has withdrawn from playing in the Russian team at the Hopman Cup," said a statement on his official Web site www.maratsafin.com.

"Although Marat has been working hard in Valencia, he feels that it would be too soon to start at the Hopman Cup and feels he should spend more time getting ready for the defence of his title at the Australian Open."

He will be replaced by 20-year-old Teimuraz Gabashvili in Perth.

The world number 12 has been troubled by a ligament tear in his left knee since Wimbledon [Images] which also forced him to withdraw from the US Open [Images].

He has not played since losing in the quarter-finals of the Cincinnati Masters Series to American Robby Ginepri in August.

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