Roger Federer says he is in "a race against time" to be fit for the Australian Open after admitting his recovery from a knee injury is taking longer than expected.
The six-times winner of the Australian Open has not played a competitive match since sustaining the injury at Melbourne Park earlier this year when he lost in the semi-finals to Novak Djokovic.
Federer said in October he was practising pain-free and expected to return to the circuit at the first Grand Slam of the year.
But speaking at an awards ceremony in Switzerland, the winner of 20 Grand Slam singles titles admitted that even if the the season's first major is delayed from January 18 until February 8 due to the coronavirus pandemic it may not give him enough time.
"I would have hoped that I would be 100 per cent in October. But I am still not today. It will be tight for the Australian Open," said Federer.
"It's a race against time for the Australian Open. I'm curious to see whether it will start on February 8. Of course, it would help if I had a bit more time.
"The second knee operation was a huge damper, but in the last six months there has been steady progress.
"Let's see how the next two months will unfold. I've been doing a lot of physio and physical work lately, now let's see how tennis is doing."
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Federer, who turns 40 in August, was voted the best Swiss athlete since 1950 at Sunday's ceremony and said it was an "incredible" honour.
"I hope there is still something to see from me next year," he added. "But if that was it, that would have been an incredible ending for me at these Sports Awards."
Confirmation of the Australian Open's change of date and rejigged schedules for the ATP and WTA Tours are expected imminently.
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