The huge 02 Arena is the perfect stage for the man expected to be challenging for grand slams next season.
Though Kevin Anderson, Filip Krajinovic, Cedrik-Marcel Stebe, Janko Tipsarevic made the shortlist for the Comeback Player of the Year gong, along with Federer and world number one Rafael Nadal, it was the latter who took the honours. "If that happens and I am healthy enough, I hope to have my chances". That stings, and Nadal is still grumbling about the way Federer disarmed his greatest weapon - red clay - by skipping the entirety of the European clay-court season.
The Spaniard insists he believes he will play on Monday in his opening match against David Goffin although he also admitted today that things were unpredictable.
But while the move paid off as he won an eighth Wimbledon title, he is not necessarily planning on doing the same again next year with 'everything back on the table' in terms of scheduling. There will come a moment where we will see the younger players on TV and we won't face them anymore.
"That's how it is".
Brad Gilbert's analysis: "If he's there, it could be a great celebration of his year".
Asked about the knee injury that stopped his progress in Paris a week ago and threatened to bring his 2017 campaign to a premature close, Nadal shrugged and raised his famous eyebrow. Nadal has faced the 36-year-old, the current world number two, on four occasions and is yet to taste victory.
Nadal then notes that all of those four defeats he suffered to Federer this year came on hard courts.
But London has been such a smash hit financially that it has held onto the event since 2009, with the contract now extended until 2020.
The ATP World Tour Finals is one of the few feathers missing from Nadal's cap. If Rafa can find his best, then we will see. But whereas Murray and Djokovic had competition from Stan Wawrinka, Kei Nishikori, and Milos Raonic (among others), Nadal and Federer may be the only ones who can stop themselves.
"I don't have to make a decision". And he wasn't at his best at the Paris Masters last week.
Gilbert's analysis: "He's not very big but is a deceptively good player".
Before the Australian Open in January, Nadal was down at No.9 in the world rankings, while Federer had plummeted to 16th. He won for an astonishing 10th career time in Monte Carlo, Barcelona and Roland Garros, and captured his fifth title at Madrid.