Novak Djokovic paid a heartfelt tribute to his rival Roger Federer on Friday, saying they had enjoyed “a decade of incredible moments and struggles” after the Swiss great announced he would be stepping down after the Laver Cup this month.

Djokovic, who responded 24 hours after Federer said he was quitting, said on social media: “Your career has set the tone for what it means to achieve excellence and lead with integrity and composure.

“It’s an honor to know you on and off the pitch and for many more years to come.”

Rafael Nadal also congratulated Federer on his extraordinary career, while Serena Williams welcomed the 41-year-old Swiss to the ‘retirement club’ after the American herself retired from the game this month.

On Thursday, Federer admitted his struggles with knee problems had forced him to end a historic career that has spawned 20 Grand Slam titles and earned him a reputation as one of the most elegant players the game has ever seen.

It didn’t come as a complete surprise as he had been out of action since a quarter-final loss at Wimbledon in 2021. After that game, he underwent his third knee surgery in 18 months when time caught up with him.

Federer said in a social media statement that his 24 years on the tour had been “an incredible adventure”.

“While it sometimes feels like it’s passed in 24 hours, it was also so deep and magical that it seems like I’ve already lived a lifetime,” said the Swiss.

Knee problems limited him to just three of the 11 Grand Slams played since early 2020 and he said his body had sent him “a message”.

“Tennis has treated me more generously than I could ever have dreamed of and now I have to realize when it is time to end my competitive career.”

Djokovic, who is six years younger than Federer and has collected Grand Slam titles when the Swiss’ powers waned, was noticed by his absence from the honors on Thursday.

But a day later he said: “Roger, it’s hard to look at that day and to put into words all that we have shared together in this sport.”

The duo played 17 matches in Grand Slam tournaments, including five finals, with Djokovic leading this neck-and-neck race 11-6.

“Your career has set the tone for what it means to achieve excellence and lead with integrity and composure,” the Serb said on a social network.

“It’s an honor to know you on and off the pitch and for many more years to come.”

Tennis has now lost two of its biggest names in quick succession after Williams, 40, was eliminated after a third-round loss at the US Open earlier this month.

“I wanted to find the perfect way to say this as you have so eloquently put this game to rest – done perfectly, as has your career,” Williams, who has won 23 major titles, said on Instagram.

“I’ve always looked up to you and admired you. Our paths were always so similar, so similar. You have inspired untold millions and millions of people – including me – and we will never forget them.”

Nadal, arguably Federer’s biggest rival on the pitch, said it was “an honor” to face him.

The pair played 40 times, including nine Grand Slam finals, with Nadal averaging a 24-16 winning record.

“It’s a sad day for me personally and for sport around the world,” Nadal tweeted.

Federer will finish his career behind only Nadal at 22 and Djokovic at 21 on the all-time list for most men’s Grand Slam titles.

Djokovic held a 27-23 win record against Federer from 50 encounters.

Wimbledon, where Federer won a record eight titles, also paid a handsome tribute to Federer.

“It has been a privilege to witness your journey and see you become a champion in every sense of the word,” the organizers tweeted.

Teenager Carlos Alcaraz, the rising man in tennis who won the US Open last Sunday to become the youngest-ever world number one, tweeted a heartbroken emoji.

The Laver Cup promises an emotional final meeting of the “Big Four” who have dominated men’s tennis for the past two decades.

Nadal, Djokovic and two-time Wimbledon winner Andy Murray will all play for Team Europe.

“I was lucky enough to play so many epic matches that I will never forget,” said Federer, nodding to his rivals.

“We pushed each other and together we took tennis to a new level.”

Federer, who has won 103 ATP titles, said in July he hoped to play another Wimbledon. He leaves with regret but added that he has lived a life many would envy.

“I consider myself one of the luckiest people on earth,” he said.

Federer won the last of his Slam titles at the Australian Open in 2018 and last played in a grand final at Wimbledon three years ago, where he lost to Djokovic despite having two championship points.