The tennis treadmill rarely stops. Andy Murray will barely have time to draw breath following his memorable week here at the Paris Masters before he is back on court practising for the year-end showpiece in London at the Barclays ATP World Tour Finals, which start next Sunday.

Once his work is done at the O2 Arena the Scot will finally have time to take a brief break before heading to Miami for his close-season training camp. By the first week of January he will be back on the road again as another season gets under way. Whether you are the new world No 1 or an up-and-coming pro breaking into the game, the men’s tennis schedule is unrelenting.

The key to Murray’s rise to the top of the rankings has been his new-found consistency. The 29-year-old Scot’s wonderful talent has never been in doubt, but until this year he had never quite matched the ability of Novak Djokovic, Roger Federer and Rafael Nadal – or indeed most of the other 22 men who have topped the world rankings – to turn in top-level performances week in and week out during a gruelling schedule that lasts the best part of 11 months.

However, Murray’s results since the start of this year’s clay-court season have been stunning. Since the Monte Carlo Masters the Scot has reached the final of 11 of the 12 tournaments he has contested and won eight of them. Having finally climbed the mountain to take the No 1 spot, he now has to prove he has the head for heights that will be required to stay there.

If he is to keep top spot for more than a fortnight Murray may well have to maintain his current form through one more tournament. Djokovic, whose run of 122 consecutive weeks at the top of the world rankings will come to an end on Monday, can yet reclaim the No 1 position by the end of the World Tour Finals, where he has won the title for the last four years in a row.

Murray, in contrast, has a surprisingly moderate record at the O2 Arena, though there have often been mitigating circumstances, such as injury issues or his understandable focus 12 months ago on Britain’s forthcoming Davis Cup final. Considering how well he has performed in front of home crowds and at indoor tournaments in the past, there appears to be no reason why he should not do well at the O2 Arena. Preserving his position on top of the rankings will provide an added incentive.

Andy Murray is crowned champion at the Paris Masters (Getty)

Murray had not expected to be breathing down Djokovic’s neck until the new year, but a combination of his own remarkable performances and the Serb’s post-French Open slump changed everything.

One of the reasons why Murray expected to put the squeeze on Djokovic in the early months of 2017 is the fact that his rival has 4,340 ranking points to defend at the start of next year. Djokovic is the reigning champion at the Qatar Open, the Australian Open and the Masters Series tournaments in Indian Wells and Miami. Over the same period Murray will be defending just 1,290 points.

Although you can never take anything for granted, it would therefore be a surprise, whatever happens in London later this month, if Murray was not world No 1 by the time the men’s tour heads for the clay courts of Europe next April. Thereafter the Scot will start to experience the pressure that Djokovic had handled so well until this summer. From the Madrid Masters onwards it will be Murray’s turn to go into tournaments most weeks knowing that he has to win the title or at least reach the final simply to tread water.

One of the imponderables in the immediate future will be the form of Djokovic, whose slide since the start of the grass-court season has been little short of spectacular. The Serb insists he has put behind him the off-the-court personal issues that contributed to his early demise at Wimbledon, but he has since been troubled by a number of physical problems and on frequent occasions has not looked like his old confident self.

The Scot is in the form of his life (Getty)

After his quarter-final defeat here to Marin Cilic, Djokovic would not be drawn into discussions about possible changes in his support team and talked enigmatically about what might lie ahead. “In terms of what the future brings to me, that's not in my hands,” he said. “I’m going to obviously keep playing at this level as long as I feel like that’s the right thing for me. So that’s all I can say.”