Roger Federer says he faces a "tight" race to be fit to play at the Australian Open.

The 20-time Grand Slam champion, 39, has not played since January, having needed two operations on a knee injury.

The Australian Open is likely to start on 8 February, delayed by three weeks because of the coronavirus pandemic.

"I would have hoped that I would be 100% in October. But I am still not today. Let's see how the next two months will unfold," the Swiss said.

Federer's last competitive match came at this year's Australian Open, where he lost to eventual champion Novak Djokovic in the semi-finals at Melbourne Park.

In February, Federer announced he had arthroscopic surgery on his right knee but hoped to return to action in time for Wimbledon - which was planned for July before being cancelled.

But in June he said he had another operation after a setback with his rehabilitation.

Following its suspension because of the pandemic, the ATP Tour resumed in early August, with the US Open closely followed by the rearranged French Open.

"The second knee operation was a huge dampener, but in the last six months there has been steady progress," Federer said during an awards ceremony in Switzerland.

"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.

"It will be tight for the Australian Open."

The Australian Open is the first Grand Slam of the tennis season and the 2021 tournament was scheduled to start in Melbourne on 18 January.

However, Covid-19 quarantine rules mean players are unlikely to be allowed to enter the state of Victoria until the end of December at the earliest.

An announcement confirming the tournament will be pushed back to 8 February is expected in the near future.