With no Andy Murray to whet home appetites, organisers of the Barclays ATP World Tour Finals must be delighted that the race to end the year ranked No.1 is alive, if only just, going into the season-ending event.

Yet to listen to the world's top two players yesterday, you would think it was already done and dusted and that, in fact, neither Rafael Nadal, the man in command, or Novak Djokovic, the No.2, is too bothered about the likely outcome.

Djokovic must win all five matches at London's O2, starting today against Roger Federer, to stand a chance but, even then, he would still have to win both his singles matches in the Davis Cup final this month. Even that would not be enough to regain top spot if Nadal wins twice in London.

Ending the year ranked No.1 is a considerable achievement but both men yesterday suggested that history reflects more favourably on those who win multiple grand slam titles than those who become No.1. "I think everyone, when they start playing sport, wants to be the best," Djokovic said after arriving from Paris, where he won a third consecutive title since the US Open. "That means being No.1. But at the same time, you are remembered for winning grand slams and that's important to me."

That the race for No.1 is even still alive is testament to Djokovic's mental and physical fortitude, having bounced back from losing to Nadal in the US Open final to win in Beijing, Shanghai and Paris. Fatigue may be a factor this week but, with the Davis Cup final on the horizon, Djokovic is determined to make the most of his return to top form.

"Considering Rafa's results since he came back from injury, losing the No.1 spot in the world was inevitable because he was winning most of the tournaments he played and he was playing the best tennis of this year," Djokovic admitted. "He deserves to be where he is.

"On the other hand, I have just tried to regroup and refocus and after the US Open final loss, I won all my matches and I've been playing my best tennis, probably, of this season, on a consistent basis. It is a priority for me to really keep on playing well, and build something for next season."

Nadal agreed that Djokovic, who has won the title in London in each of the past two years, deserves to be the clear favourite but, having missed seven months through injury before his return to action in February, Nadal's rise back to the top, with two more grand slam titles in the bag, is little short of phenomenal.

"It's the most difficult thing that I did in my career, sure, 100%," said Nadal, who today plays compatriot David Ferrer who beat him in Paris last week. "[But] the emotions during the tournaments were much more special for me than being No 1. It's something I have been in the past. I've already finished year-end world No.1 twice before. If it happens again, great, but I feel that at the end of my career that's not going to affect if I am a better or worse player in terms of the history of tennis."

Stanislas Wawrinka, meanwhile, has been walking around the O2 with the look of a child in a sweet shop, eyes wide and soaking everything in on his debut at the Tour Finals. The Swiss responded with a fine performance as he beat Tomas Berdych 6-3, 6-7, 6-3 in the first match in Group A.