The amity between Andy Murray and Novak Djokovic, the enduring rival Murray has deposed as world No1, seems as genuine as it is recurring. Certainly the mutual praise they swapped in separate interviews at the O 2 Arena on Friday had a greater ring of sincerity about it than that attending another transfer of power across the Atlantic.

They did not play each other when the power shift struck – Djokovic went out in the quarter-finals in Paris last week against Marin Cilic and Murray went on to win the final against John Isner.

But there was no awkward White House moment, just a click of the calculator to catapult the Scot past the Serb, smoothing the way to what will be either a defining coronation for Murray or a spirited revival for Djokovic at the ATP World Tour Finals in London that start on Sunday.

Murray said of Djokovic’s post-Roland Garros slump and downbeat demeanour: “He’d been playing great for years. So, not to play his best for a couple of months, I’m sure for him it’s not too much to worry about. I imagine shortly he’ll be back to playing his best.

“He’s won here the past four years so there’s no reason to think that he won’t have a really good tournament.”

Djokovic, dignified in triumph as well as disappointment, said of Murray: “I have only words of praise for what he has achieved in the last year or so. He has had the best clay-court season of his life, playing three finals of the big events and winning one in Rome [against Djokovic], winning every event on grass court. He has had an incredible run and definitely is a well deserving No1 player.”

However, confirming that his competitive instincts are still strong, he added:“Whether or not he can sustain that is not a question for me.”

Except it is. If Djokovic wins every match, he will be No1 again. There are other scenarios, but that is the bottom-line he will have at the forefront of his mind when he plays Dominic Thiem in the first singles match on Sunday. Murray, who opens against Cilic on Monday night, has only to match Djokovic, or stop him in the final, and the prize is his.

There are eight gunslingers in town, some shooting straighter than others. Stan Wawrinka invariably finishes strongly here and Cilic, who lost to Isner in the semi-finals in Paris, will be dangerous. Milos Raonic is injured, Kei Nishikori always seems as he is just about to be, Gaël Monfils is the eternal wildcard and Dominic Thiem, one of the best young players on the rise, has nothing to lose.

But everyone knows that the perfect scenario on Sunday week would be Murray facing off against Djokovic for the 35th time.

For Djokovic, the motivation is to win back what for so long had been his. “You do have days when you are feeling maybe less determined to play,” he said. “But, as long as the days when you are feeling positive are there … that is the case with me.

“Even after playing 10-plus years. I feel like I still have a lot of gas in my tank and still a lot more years ahead of me. I still feel great joy when I play.”

Both say their families mean more to them than beating each other. “This year I consider the best I’ve had on court,” Murray said. “Away from the court, it has been by far the best year that I’ve had, a big change [the arrival of his daughter, Sophia] but a great change. I’ve really enjoyed being a parent.”