Roger Federer's last ever match - a moment tennis hoped would never come - will happen later at the O2 in London at the Laver Cup.
It is a tournament he created with his agent to honour his idol, Rod Laver.
Maybe now he should rename it going forward... after himself.
On paper, statistically, he can perhaps no longer be called the greatest of all time, his tally of 20 grand slam titles has been surpassed by both Rafael Nadal and Novak Djokovic.
However, what he did for the game is unrivalled - how he played the game is unrivalled.
His place in history is cemented. Tennis will never forget Roger Federer, no matter what happens going forward.
First, there is the beauty of how he played. The footwork of a dancer, fluid effortless strokes, the rapier one-handed backhand, the easy power of his forehand, and the guile of his serve - not to mention his skill at the net and his wits on the court.
No shot ever seemed too difficult, execution most often 10 out of 10.
At the peak of his powers did Roger actually have a weakness? He always seemed to find a way to win unless one other of the 'big four' was out to stop him.
One photographer quipped that he'd tried for 10 years to get a flustered shot of Roger, but he never did.
Cool under pressure, always immaculately turned out, barely a hair out of place under the perfect headband, no wonder the All England Club loved him. But then everyone loved him.
A temperamental racket-throwing teen
It's hard to imagine that he was once an erratic, temperamental racket-throwing teen, as the grown Roger always seemed in control. The fans loved that - there was never an on-court outburst, an embarrassing scene.
Many would wave Swiss flags and cheer for Roger even if they weren't Swiss, such was the effect he had.
Apart from the artistry with which he plays the game, tennis will miss what he did for the sport off the court. Generous with his time to fans and media, press conferences were conducted in triplicate - English, French, and Swiss German.
Before Wimbledon he'd give all the crews, rights holders and non-rights holders, something. One answer from Roger was worth five from everyone else, he loved to talk.
I doubt he ever made it on time to the Wimbledon Champions Dinner. He'd still be there in the basement of the Club, in the dark, speaking to the likes of me at 9 or 10 at night. Enjoying re-living his latest Wimbledon triumph.
Even after his eighth victory at the age of 35, in 2017, he was still enthusiastic about the process. He just enjoyed his victories and everyone around him did too.
A perfect goodbye
I was once asked to put a question to him about the America's Cup yacht race because Sky Sports were covering it and the Swiss team was leading.
I wasn't expecting him to say much but, of course, Roger had an anecdote: "Funny story I train in Dubai and so did they and I saw them on the way to practice one day and they invited me to join them on their boat, so I did.
"Pretty soon I needed to pee and asked where the bathroom was and they pointed to the sea - I didn't expect that on such an expensive boat!"
It is fitting that Roger's last match will be as a doubles partner to his greatest rival Rafa Nadal. He joked that Rafa's in charge because it's been so long since he played.
His troublesome knee, which has kept him out of tennis since Wimbledon 2021, finally calls time on one of the all-time greats of the sport.
He never planned to retire at the Laver Cup, which is a bit like the Ryder Cup but for tennis - Europe v the Rest of the World - but he says his knee isn't up to singles matches anymore.
And it's such a Federesque way to bow out: his long-term rivals will be on the same team as him one last time, Rafa, Andy Murray, and of course Novak Djokovic.
Players he's inspired to great things themselves. Players who've shared some of their biggest moments on the court with him on the other side of the net. The four have won 66 grand slam titles between them.
Rafa, Djokovic and Murray get to share Federer's goodbye, be part of the historic sporting moment, and put an arm around his shoulders if he gets emotional (and he will).
As goodbyes go, it's pretty much perfect.