Tennis’s biggest name is in doubt for the rescheduled Australian Open, with Roger Federer conceding that his recovery from a knee injury is taking longer than expected.

The 20-times grand slam champion has not played since being injured en route to the semi-finals at Melbourne Park last year.

He revealed at an awards ceremony in Switzerland that even the delayed start to the season’s first major, likely to be February 8 instead of January 19, may not be 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,” Federer said.

“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.”

Turning 40 next August, Federer – a six-times champion in Melbourne – said his 2021 priorities remain Wimbledon, the US Open and Tokyo Olympics, where he will be bidding for a first singles gold medal, the only major prize still eluding him.

Federer underwent a second round of surgery on his right knee in the middle of the year, having suffered a similar injury during his five-set Wimbledon semi-final loss to Milos Raonic in 2016.

On that occasion, the Swiss marvel made an extraordinary comeback to win his fifth Australian Open crown in 2017 with an epic five-set final triumph over Rafael Nadal in his first official tournament appearance in six months.