Defending champ out of Australian Open

MELBOURNE, Jan. 10 (UPI) -- Defending champion Marat Safin says he will not compete in the 2006 Australian Open because of a knee injury.

Safin, 25, has been sidelined since last summer's Cincinnati Masters due to the injury. He won last year's first Grand Slam championship by beating Lleyton Hewitt in four sets.

"I am very sad that I cannot go to the Australian Open and defend my title as champion," said Safin. "I have been working very hard and (the knee) is a lot better. But it would not be right to go to a Grand Slam and put so much test on my knee right now."

Safin, a Russian, also won the 2000 U.S. Open while finishing second in 2002 and 2004. He plans on returning to the ATP for an event in Marseille in mid-February.

He first injured the knee at Wimbledon last year.