I have been working very hard and my knee is a lot better but it would not be right to go to a Grand Slam and test my knee right now. I am sorry to all my Australian fans but I will be back next year.

I am very sad that I cannot go to the Australian Open to defend my title. I have been working very hard and it is a lot better.

I am very sad I cannot go to the Australian Open to defend my title as champion.

But I have to live with that, work on my serve and get ready for the Australian Open.