TURIN, Italy — With top-ranked Novak Djokovic and most of the world’s other top men’s tennis players gathered here for the ATP Finals, the absentee Roger Federer gave an update.

It was far from reassuring for all those eager to see him return to the tour.

In an interview that appeared in French in a Swiss newspaper, La Tribune de Genève, Federer, 40, ruled out playing in next year’s Australian Open, which is set to begin on Jan. 17 and is the first Grand Slam tournament of the season.

More unexpectedly, he also all but ruled out Wimbledon, which begins in late June.

“The truth is that I would be incredibly surprised to play Wimbledon,” he said.

For now, Federer, one of the greatest players in tennis history, continues to recover from his fourth and most complicated knee operation, which he indicated required surgery on both the meniscus and articular cartilage in his right knee. He said his tentative plan was to return to competition at some stage in the Northern Hemisphere summer next year, which could mean a comeback on North American hardcourts. But that timetable is far from a sure thing. For now, he said, doctors have told him he can begin running in January but probably not return to full tennis training until “March or April.”

“We can sum up my ambitions this way: I want to find out one more time what I’m capable of as a professional tennis player,” he said. “I am fighting for that, and I’m very motivated. I feel the support of my team and my family. We’d all like for me to be able to say farewell on my terms and on a tennis court.”

Federer, still ranked 16th, has played only 19 tour matches in the last two seasons and not at all since losing, 6-3, 7-6 (4), 6-0, in July to Hubert Hurkacz in the quarterfinals of this year’s Wimbledon. Federer’s right knee was troubling him during that match, as it had been for much of the grass-court season, but the lopsided score of the final set was particularly deflating. Federer has developed a deep connection with the All England Club, where he has won eight Wimbledon singles titles, a men’s record.

He said in the Tribune de Genève interview that he hoped to give his fans a better memory.

“The simplest thing would almost be to say: ‘That’s it. I gave a lot, received a lot, let’s stop it all,’” he said. “But to give everything to come back one more time is also my way of thanking the fans. They deserve better than the image I left during the grass-court season this year.”

Federer speculated that he might not be able to return until 2023 from this operation, which he said was more serious than his previous knee operations.

“If you push the reasoning further, it doesn’t make much difference whether I return in 2022 or not until 2023,” he said. “At 40 or 41, it’s the same. The question is whether I can keep pushing myself hard day after day. Today, my heart says yes. So I’m going step by step. It’s another challenge like I’ve faced many times in my career, sometimes without the public realizing it. And even if I know very well that the end is near, I want to try to play some more big matches. It won’t be easy but we’re going to try.”

Despite his smooth game, Federer has played through plenty of discomfort through the years: dealing with lower back problems from his early 20s and with recurring knee pain in the second half of his career. There is, of course, the possibility that he continues with his rehabilitation and concludes that a comeback is impossible. Doctors who have not treated Federer have suggested that the long recovery period indicates that this latest operation was an attempt to regenerate articular cartilage in his right knee, perhaps with microfracture surgery.

“Basically, there are two types of knee cartilage: the meniscus is one, and the articular cartilage is the other,” said Bill Mallon, an American orthopedic surgeon and former professional golfer. “Articular cartilage is the covering of the bone that allows almost friction-free movement of the knee joint. Articular cartilage has very little blood supply, so it regenerates very poorly, if at all. And its ability to regenerate is completely age dependent. The younger you are the more chance you have of that cartilage regenerating.”

Federer remains tied for the men’s record of 20 Grand Slam singles titles with his longtime rivals Rafael Nadal and Djokovic. Nadal, who has been out of action since August because of a recurring foot problem, has announced that he intends to return to the tour in January. But Nadal, 35, and Djokovic, 34, are significantly younger than Federer, and the other men taking part in the elite ATP Finals are even younger, all in their early to mid-20s.

“Obviously Roger is an icon of our sport, and people around the world love him,” Djokovic said on Wednesday after qualifying for the semifinals in Turin with a 6-3, 6-2 round-robin victory over Andrey Rublev. “They love watching him play, love seeing him around.” Djokovic added, “I’m sure he doesn’t want to end his career this way.”

Nicholas DiNubile, an American orthopedic surgeon who specializes in knee surgery, said it would be challenging to return to the tour after articular cartilage surgery.

Federer said he had surgery this time not only so he could resume his tennis career, but so he could also live a more active life in the years ahead, playing sports with his children and friends. But Federer, an optimist by nature, is not yet prepared to aim for retirement. He wants more of what only elite competition can provide.

“If I am committing myself fully to my rehabilitation, it means there’s a chance I can come back,” he said. “If I am doing strengthening, bike, pool and balance exercises, and if I was working my upper body when I was on crutches, it’s because I believe. Will I come back for a short run, or something bigger? Nobody knows. Not the doctors. Not me. But I am fighting for that.

“Let’s be clear: My life is not going to fall apart if I don’t play another Grand Slam final. But it would be the ultimate dream. And in fact, I still believe. I still believe in these kinds of miracles. I’ve experienced them. Sports history writes them sometimes. I’m realistic. It would be an enormous miracle. But in sport, miracles exist.”