Roger Federer decided to miss the Australian Open because wife Mirka opposed having to spend a full fortnight in quarantine, a leading official has claimed.

It was widely assumed Federer's reason for skipping the upcoming grand slam related to the knee surgery he underwent last season.

He had hinted as much, and agent Tony Godsick referred to the knee rehabilitation when announcing in December that the Swiss great would not travel to Melbourne.

But Andre Sa, the head of player liaison at Tennis Australia, says Federer pulled out when it became apparent his wife and children would be holed up in their hotel accommodation for two weeks.

The players travelling to Australia must all quarantine to avoid any possible spread of COVID-19, but they are allocated five hours per day in which they can leave their rooms to train and practise with specified hitting partners.

Sa, a former top-20 doubles player, told Band Sports in his native Brazil that he discussed with father-of-four Federer the practicalities before the 20-time grand slam winner reached his decision.

"The main reason was the quarantine," said Sa. "I talked to him a month ago and he had two options. He could come with the whole family and do the quarantine.

"The problem is that Mirka and her children couldn't leave the room. They would have to stay 14 days in the room. The exception is only for players.

"He could go out, train and come back, but the family couldn't. Mirka did not approve the idea.

"The other option would be for him to come alone. Only there would be at least five weeks away from family and children. And then he said, 'Dude, 39, four kids, 20 grand slams. I'm no longer at the stage to be away from my family for five weeks.'"

Former world number one Federer has not played a tournament since losing to Novak Djokovic in the semi-finals of the Australian Open last year.

This year's edition of the grand slam has been delayed by three weeks to a February 8 start, due to factors tied into the pandemic.