Team World has never won the cup, and now it will face the rare dream team of Novak Djokovic, Rafael Nadal, Andy Murray and the retiring Roger Federer.When he announced his retirement from professional tennis last week, Roger Federer put a cap on one of the most storied careers in the sport. That he chose to end competitive play at the Laver Cup, the Ryder Cup-style event that he and his management team founded in 2017 as a chummy atmosphere of star players to showcase great tennis, speaks volumes.He will say goodbye to his fans while competing alongside his greatest rivals — Rafael Nadal, Novak Djokovic and Andy Murray — demonstrating just how important the Laver Cup, which starts on Friday in London, is and will continue to be for Federer.“This is a bittersweet decision because I will miss everything the tour has given me,” he said on Twitter on Sept. 15. “But at the same time there is so much to celebrate. I consider myself one of the most fortunate people on Earth. I was given a special talent to play tennis, and I did it at a level that I never imagined, for much longer than I ever thought possible.”The Big Four, as they have been known, have faced off countless times at Grand Slam events, but never have they been teamed together, until this weekend when they form the nucleus of Team Europe in the Laver Cup.Those four players have been formidable. Between them, they have won 329 ATP titles over the last two decades. They have amassed 66 major championships, including 19 at Wimbledon, 17 at both the Australian and French Opens and 13 at the United States Open. They have won more than 4,000 matches and earned nearly half a billion dollars in prize money.Novak Djokovic, left, and Andy Murray, will also play for Team Europe. This is the first time the four players, who have won a total of 66 major championships, have all played together on a team.Clive Brunskill/Getty ImagesEvery year since 2004, one of them has ended the season ranked No. 1 in the world. Federer, the oldest at 41, won his first match in September 1998 just after his 17th birthday, when he beat Guillaume Raoux in Toulouse, France.“Let me first say, this is legendary,” said a grinning Stefanos Tsitsipas, who is ranked No. 6 in the world and is playing in the Laver Cup for the third straight time. “This team is a joke. This is Michael Jordan with the Chicago Bulls.”When the Laver Cup started, Federer said at the time, “We need to see the legends of our sport more frequently, who we’d like to thank. It’s not just the players standing on court today, there’s so many more that have paved the way for us so we can enjoy playing in front of a crowd like this, earn a living and live our dream. All of us, all we wanted to do all our life is play tennis, and here we are.”The fifth edition of the competition will again include singles and doubles matches and also feature Casper Ruud, No. 2, and Tsitsipas for Team Europe against a contingent representing the rest of the world. Called Team World because it includes players from other parts of the globe, the team includes Taylor Fritz, No. 12; Felix Auger-Aliassime, No. 13; Diego Schwartzman, No. 17; Frances Tiafoe, No. 19; Alex de Minaur, No. 22; and Jack Sock, No. 128.Tiafoe, who upset Nadal in the U.S. Open and then beat Andrey Rublev before falling in the semifinals to the eventual champion, Carlos Alcaraz, is a last-minute replacement for John Isner, who fractured his left wrist at the U.S. Open.The captain of Team Europe is the six-time French Open, five-time U.S. Open champion Bjorn Borg. Leading Team World, which has lost every year since the event’s inception, is the seven-time major winner John McEnroe.“I love being part of this event in any way, shape or form,” said McEnroe, an ESPN commentator. “Just seeing my buddy Bjorn on the other side. Obviously, my days are getting numbered because my record isn’t too good. But the law of averages states that at some point Team World can come through. Since it’s more unpredictable this year we go in with a solid puncher’s chance.”The last time Federer, Nadal, Djokovic and Murray were in the same major tournament was the 2019 Australian Open when Djokovic won his record seventh championship.McEnroe’s uncertainty centers on the health and ages of Federer, Nadal and Murray and the lack of tournament play for Djokovic. The average age of Team Europe’s four marquee players is almost 37, while the average age of Team World is about 26.Djokovic, 35, who was barred from playing the Australian Open and the U.S. Open because of his refusal to be vaccinated against Covid-19, has played just seven tournaments this year. He won two of them, including Wimbledon, but his ranking has dropped to No. 7.Murray, 35, has shown stretches of brilliance this year, notably when he beat Tsitsipas and Nick Kyrgios en route to the final in Stuttgart in June. But he also failed to win back-to-back matches from mid-January to early May.Nadal, 36, has been hampered ever since he tore an abdominal muscle at Indian Wells in March. Then, after beating Fritz in a five-setter in the Wimbledon quarterfinals, Nadal was forced to withdraw before his semifinal match against Kyrgios. He also struggles with chronic foot pain.Still, Nadal is looking forward to supporting his longtime friend Federer. Asked if he would play doubles with him, as he did in a win over Sock and Sam Querrey in 2017 — a match that featured a near midair collision and giggles between them — Nadal said he would jump at the chance. “If the captain chooses us as teammates, why not?” Nadal said with a smile.Federer will clearly be the biggest draw of the weekend. He has not competed since last year’s Wimbledon, when he lost in the quarterfinals to Hubert Hurkacz. Federer had knee surgery last year in August and struggled to return to the tour, prompting his decision to retire.Roger Federer played with Alexander Zverev in a doubles match at the 2019 Laver Cup.Fabrice Coffrini/Agence France-Presse — Getty ImagesFederer is part owner of the Laver Cup. He missed last year’s event because of his knee, but arrived on crutches to cheers from the fans and sat on the bench encouraging Team Europe. This year he will do everything he can to play, even if it is just in doubles with Nadal.For the younger players, just being able to share the Laver Cup experience with Federer is valuable.“I’ve learned so much from these greats,” said Tsitsipas, who played doubles with Federer at the 2019 Laver Cup. “I get to share something very meaningful with them through the course of the three-day performance period. More than that, we get to connect and share great ideas on court, off court, be part of something very extraordinary for our sport.”When asked the nature of those off-court experiences, Tsitsipas deferred.“I signed an N.D.A., so I’m not allowed to share,” he said with a laugh, referring to a nondisclosure agreement.As for Ruud, who played in his first Laver Cup last year in Boston and finished second in the U.S. Open this month, just playing with the Big Four is magical.“It’s going to be so special, and a small dream come true,” Ruud said. “For all the tennis fans around the world to see the Big Four on the team together for the first time, and maybe the last time. To know that I can be a part of that team and learn from them and be around them for that week will be incredible.”“Roger has always been an inspiration to everyone,” Ruud added. “For me as well. He shows that what we thought was impossible is possible. I can’t wait to see him at the Laver Cup.” More