LONDON: Some of the most iconic moments of Roger Federer's glittering career featured Rafa Nadal across the net but on Friday his great Spanish rival will be alongside him for his final bow.

The 41-year-old Federer, winner of 20 Grand Slam titles and for many the greatest player to wield a tennis racket, is back in one of his favourite cities to bring down the curtain on a 24-year professional career that scaled staggering heights.

He will partner Nadal for a doubles match on the opening day of the Laver Cup at London's O2 Arena -- a three-day team event in which Europe takes on the Rest of the World.

Federer announced last week that the Laver Cup would be his final competitive event having failed to overcome a nagging right knee issue that required multiple surgeries.

While that injury means he is unable to feature in a singles match here in London, he will conclude the opening day alongside men's record 22-time Grand Slam champion Nadal as they face American duo Jack Sock and Frances Tiafoe.

As farewells go, it simply could not be better.

Federer played Nadal 40 times in one of the most compelling rivalries witnessed in tennis.

Who could forget their 2008 Wimbledon final when Nadal denied Federer a sixth consecutive title, the time Federer cried following defeat in a brutal 2009 Australian Open final, or the 2017 Australian Open final when Federer ended a five-year wait for his 18th major title by defeating Nadal in a classic.

No quarter has ever been given on the court but despite the ferocity of their duels, deep respect endures.

Which is why Federer said earlier this week that playing with Nadal would be a beautiful way to conclude a career that caught fire when he claimed his first Grand slam title in 2003 by winning Wimbledon.

Europe's captain Bjorn Borg, not surprisingly, granted him his wish.

"It's going to be a different kind of pressure to be part of this historic moment," Nadal told reporters.

"It's going to be something amazing and unforgettable for me. I'm super excited. maybe we can create a good moment and maybe win the match."

Federer cut a relaxed figure as he sat with his team mates, including 21-time Grand Slam champion Novak Djokovic and twice Wimbledon champion Andy Murray.

But he said the emotions could hit him on Friday.

"I'm not sure if I can handle (all the emotions) but I will try," Federer, whose presence had fans flocking to watch practice sessions on Thursday, told reporters.

"This one feels a whole lot different. It's super special playing with Rafa. "Feels very different you know."

Nadal was asked to highlight some of his best moments against Federer, not surprisingly picking the 2008 Wimbledon final as one of his most cherished.

He also spoke warmly of their enduring friendship.

"I think we are very proud it's been a friendly rivalry," said Nadal, who beat Federer in six Grand Slam finals.

"Not easy because we are playing for such important things for our tennis careers, but at the same time we were able to understand that personal relationships are more important than sometimes professional things.

"Tomorrow is going to be special thing."

Rest of the World captain John McEnroe said there had been some "coin flicking" to see who would face Nadal and Federer in Friday's doubles -- saying that whatever the result of the match it would be a magical night for tennis.

"It's a very unique situation that we are all fortunate enough to be around," McEnroe said. "This is like an incredible moment for our sport.

Sock said he was stoked to be part of an iconic night while Tiafoe, who reached the U.S. Open semi-finals, added: "I'm just excited to play two up-and-comers!

"Both guys are absolute legends, and obviously it's Roger's last dance."

Sock opens play in Friday's first singles against U.S. Open runner-up Casper Ruud while Murray is the evening warm up act against Alex de Minaur.