Roger Federer is targeting a return to the circuit in mid-2022, the Swiss star said Wednesday, hoping to play some big matches once again before bowing out in style.

The 20-time Grand Slam champion, who turned 40 in August, is working his way back from a persistent right knee injury that restricted him to just five tournaments this year.

Federer said the Australian Open in January was out of the question, while participation in the French Open in May and June and his favourite major, Wimbledon in June and July, was highly unlikely.

"The truth is I would be incredibly surprised to play Wimbledon, which is to say that Australia does not even come into play," he said in an interview published in the Swiss newspapers 24 Heures and Tribune de Geneve.

Federer had been out for more than a year with two surgeries on his right knee before getting back onto the tour in 2021.

But he played only 13 matches, and underwent a third operation on the knee following his quarter-final defeat at Wimbledon in July.

He said he was targeting a "return to competition in summer 2022", but warned that "the next four or five months are going to be decisive" for his comeback.

- Road to recovery -

After this year's Wimbledon, Federer missed the Tokyo Olympics to undergo more surgery on his right meniscus, followed by a cartilage operation.

"This operation, I was going to have to do it anyway for my long-term well-being... to be able to ski with my children, to play football or tennis with my friends in the decades to come. My first motivation was to get back in shape for my life as a man," he said.

Federer said he will start light running again in January and then only take up "training that looks like tennis" in March-April.

"I want to go and see one last time what I am capable of as a professional tennis player," he said.

"We would all like that I could say goodbye in my own way and on a tennis court.

"And if we push the reasoning, playing again in 2022 or 2023 no longer makes a big difference: 40 or 41 years old, it's the same thing."

Federer said the question was more one of whether he was prepared to put himself through the pain day after day.

"Today, my heart answers yes. So I take things step by step," he said.

"And even if I know full well that the end is near, I want to try to play in some big matches again."