US Open champions past and present Andy Roddick and Carlos Alcaraz led a swathe of social media tributes to Roger Federer after the 20-time grand slam winner announced his retirement.
Federer, who has not played competitively since exiting Wimbledon at the quarter-final stage last year, revealed on Thursday that next week's Laver Cup will be his farewell tournament.
Federer appeared at a parade of former champions at Wimbledon earlier this year and hinted at his desire to feature at the All England Club once more, but his upcoming outing in London will now represent the swansong to his stunning career.
The Swiss great will become the first of the ATP Tour's 'Big Three' to exit the sport, with Rafael Nadal and Novak Djokovic still active.
While Nadal and Djokovic have each surpassed Federer's tally of 20 major titles this year, the 41-year-old overtook Pete Sampras' previous record of 14 grand slam titles by beating Roddick in the 2009 Wimbledon final.
Roddick was among the first to pay tribute to Federer's achievements on Thursday, writing on Twitter: "Cheers Roger. Thanks for the shared memories my friend.
"It was an honour to share time/experiences on the most hallowed grounds in our sport. Don't be a stranger."
Alcaraz, who clinched his first grand slam title and became world number one with a US Open final win over Casper Ruud on Sunday, simply wrote: "Roger…", accompanied by a heartbroken emoji.
Milos Raonic has seen his efforts to win a major title foiled by the presence of the 'Big Four' – with Andy Murray beating him on his sole grand slam final appearance at Wimbledon in 2016 – but he also showed his appreciation for Federer's impact.
"Thank you for doing more for tennis than any single individual," Raonic wrote. "Thanks to you competitors and fans across the world get to experience and enjoy it all over the world.
"Congratulations on your achievements and the people you continue to impact in and away from tennis."
Juan Martin del Potro, who prevented Federer from winning six consecutive US Open titles with a five-set success in the 2009 final, labelled the 41-year-old irreplaceable, declaring: "I LOVE YOU, Roger.
"Thank you for everything you've done in tennis and with myself. [The] tennis world will never be the same without you."
Former player-turned presenter James Blake added: "Roger, there was and never will be anyone like you. You crushed me on the court, but were so nice and genuine that I couldn't hate you for it.
"You made the game better on and off the court and you will be missed. Good luck, you have earned all the success and joy in the world."
Garbine Muguruza tweeted: "RF" followed by a heartbroken emoji.
Those who shared a court with Federer were not the only ones to pay tribute, however.
A tweet from Wimbledon's official account read: "Roger, where do we begin? It's been a privilege to witness your journey and see you become a champion in every sense of the word. We will so miss the sight of you gracing our courts, but all we can say for now is thank you, for the memories and joy you have given to so many."
Roland Garros' official account tweeted: "An inspiration on and off the court. Thank you, Roger."
The US Open's handle simply posted: "Thank you, Roger."