Roger Federer is unlikely to play in next year's Australian Open as he recovers from injury.

Swiss Federer, 40, has not played since losing in the Wimbledon quarter-finals in July and having more knee surgery.

"I think the Australian Open is not a real possibility right now," Ljubicic told Stats Perform.

"I think there are very few chances, he is still recovering and knowing him, he wants to be sure he can play to win the tournament and be at 100%.

"He will go step by step because he is 40 years old now and he needs to be patient. He cannot recover as quickly as he used to."

Ljubicic, a former world number three, said he was certain that Federer was not thinking about retiring just yet.

"We have spoken and I can guarantee he wants to return to playing tennis," he added.

"When he decides to stop he will retire, but I don't think it's going to happen all of a sudden."

Speaking in September, former world number one Federer said he was "feeling good" after his third round of knee surgery, having also had two operations in 2020, and was not going to rush his return to action.

He is tied with Rafael Nadal and Novak Djokovic in the race to be the most successful men's singles Grand Slam champion of all time and Australian Open organisers would have been hoping to have all three at Melbourne Park for the 2022 event, which starts on 17 January.

Nadal, who has been struggling with a foot injury, has said he will be there, but Djokovic has declined to confirm his presence until Tennis Australia reveals the health protocols for the tournament.

The Serb world number one has not confirmed whether he has been vaccinated against Covid-19, a prerequisite for entering the country under current rules.