It was in London where Roger Federer became a genuine star: strolling onto Centre Court at Wimbledon in 2001 with a ponytail and nondesigner stubble and then coolly and stylishly ending the long reign of Pete Sampras with a fourth-round upset.

So, it seems fitting, or at least symmetrical, that Federer will end his competitive tennis career in London, too, playing one last doubles match in the Laver Cup on Friday night, alongside his friendly archrival Rafael Nadal.

It of course would have been a fuller circle for Federer’s final act to have come at Wimbledon. But that would have meant playing best-of-five sets on often-slick grass, and though his spirit is still willing, his 41-year-old, postoperative knees are not.

Instead, the end will come indoors at O2 Arena in a team event Federer conceived with his agent, Tony Godsick, and launched in better, healthier days in 2017, when he was in the midst of the surprising late-career revival that cemented his place among the exceptional athletes of this age or any other.

Though it was far from a sure thing, he endured with excellence: breaking into the top 20 as a teenager and becoming the oldest No. 1 in the history of men’s tennis at age 36 in 2018.

On Wednesday at a news conference at the O2 Arena ahead of the Laver Cup, Federer was asked how he hoped people would remember him and what made him proudest about his career.

“Longevity” was the answer.

“I was famous for being quite erratic at the beginning of my career,” he said. “And then to become one of the most consistent players ever is quite a shock to me, as well.”

Federer said he felt back then that he could compete for any title for “15-plus years.”

“That has been a privilege,” he said. “I think looking back, that has a special meaning to me because I always looked to the Michael Schumachers, Tiger Woods, all the other guys that stayed for so long at the top that I didn’t understand how they did it. Next thing you know, you’re part of that group, and it’s been a great feeling.”

Federer did it with a unique blend of improvisational talent and carefully conceived structure.

He had an undeniable gift for the game, including supreme hand-eye coordination and what Marc Rosset, the most successful male Swiss player before Federer, rightly identified as exceptional “processing speed” that allowed Federer more time to create great shots on the fly and then finish them with an extra flourish.

But Federer also learned how to manage his time, build an excellent support team and maintain his positive energy. He scheduled judiciously and took genuine breaks from the grind of the tour while also relaxing while playing on the tour. Many an opponent can recall a pleasant chat with Federer in the locker room shortly before a match, and that he could then don his game face in an unsettling hurry.

In an interview in 2019, he explained his recipe for success.

“As much as I take things very serious, I am very laid back, so I can really let go very quickly. I truly believe this is a secret for a lot of the players and for the young guys is to be able, when you leave the site, to say: ‘OK, I’m going to leave it behind,’” he said. “‘I still know I’m a professional tennis player, but I’m relaxing. I’m doing it my way, whatever helps me decompress.’”

Federer punctuated this by clenching his left fist.

“Because if you are constantly like this, that’s when you burn out,” he said, looking at his fist.

Federer, by design and by embracing the process, never did burn out. Instead, his body gave out after multiple knee surgeries and long cycles of rehabilitation. He said he still had hope at Wimbledon this year, when he made a surprise appearance for a ceremony honoring the 100th anniversary of Centre Court, that he could return to play there at least “one more time.”

But shortly after that emotional visit, he said he received the results of a magnetic resonance imaging scan on his right knee that made the reality clear.

“I was already walking on thin ice for a long time,” he told the Swiss press this week.

He called the decision “bittersweet” when he announced it last week, and then broke down the bitter and the sweet on Wednesday.

“The bitterness is you always want to play forever,” he said. “I love being out on court. I love playing against the guys. I love traveling. I never really felt like it was that hard for me to do.”

He said he enjoyed the winning and learned from losing.

“It was all perfect,” he said. “I love my career from every angle. That’s the bitter part. The sweet part was that I know everybody has to do it at one point. Everybody has to leave the game. It’s been a great, great journey. For that, I’m really grateful.”

Asked for the highlights, Federer pointed to the upset of Sampras in 2001, his first major title at Wimbledon in 2003, his first and only French Open title in 2009 and the Australian Open victory in 2017 that launched his comeback.

But he knows the lowlights are intrinsically part of the story, too: defeats like the 2008 Wimbledon final against Nadal and the 2019 Wimbledon final against Novak Djokovic, which as it turned out, was Federer’s last chance to win a 21st major singles title.

“I’m probably famous for having some tougher losses, as well,” he said. “But then also dealing with them and seeing it as an opportunity to get better, to grow from it. I’m happy I don’t have flashbacks to tough moments in my career.” He added: “I’m happy that my brain allows me to think this way, because I know it’s not easy to push sometimes defeats and those things away.”

Passed in the Grand Slam singles title count by Nadal and Djokovic, who both hold a head-to-head-edge over him, Federer is no longer an obvious pick as the greatest player of this golden era. But he was clearly that player at one stage: in 2009 when he broke Sampras’s then-existing record by winning his 15th major at Wimbledon.

“Anything after that was a bonus,” he said. “Obviously the last few years have been what they have been, but I’m very happy that I was able to win another five slams from 15 on. For me it was incredible. Then I made it to over 100 titles, and all that stuff has been fantastic. Then just my longevity is something I’m very proud of. Don’t need all the records to be happy; I tell you that.”

Federer addressed many topics on Wednesday in his familiar rambling English and later in French and his native Swiss-German.

That polyglot performance also seemed fitting, considering that Federer has been an accessible champion, answering and generally respecting each question over the many years. He also has a fiercely private side, which helps explain how he was able to keep his retirement decision from going public for nearly two months.

He could have signed off on Instagram, which did not exist when he started his career. Instead, he will play one last match in London, which certainly won’t hurt the profile of his brainchild, the Laver Cup, but also seems a reasonable way to call it a day.

The O2 is sold out for all five sessions (no surprise despite the high price of entry), but opening night on Friday seems to be the must-have ticket. Win or lose — and who really cares at this stage? — there will be roars, and there will be goose bumps. And though there were surprisingly no tears from Federer on Wednesday, there should be a few of those, too.