Russian Marat Safin will not defend his Australian Open title, saying on Wednesday that he had not recovered sufficiently from a knee injury.

"I am very sad that I cannot go to the Australian Open to defend my title as champion," Safin said on his website.

"I have been working very hard and it is a lot better. I am sorry to all my Australian fans but I will be back next year," he said.

Safin beat world number one Roger Federer in the semi-finals in Melbourne last year before toppling local favourite Lleyton Hewitt in the final to win his first Australian Open title.

Safin tore a knee ligament at Wimbledon and has not played since the Cincinnati Masters Series in August.

The Australian Open begins in Melbourne on Monday.