analysis A number of key questions will be answered at the 02 Arena, writes Hugh MacDonald

THE great and the merely very good of world tennis have descended on London for the annual end of season bun fight that carries an unusual significance this year. The best eight players in the world normally congregate for the Barclays World ATP Tour Finals in varying degrees of exhaustion and/or are hampered by injuries sustained after the extraordinary demands of completing a campaign that started 11 months ago on the other side of the world.

The O2 Arena in London next week, however, should be the venue for an intriguing session of Question Time. The very good – Mardy Fish, Jo-Wilfried Tsonga , David Ferrer, and Tomas Berdych – will face the gentle inquisition that low expectation dictates. They are not favoured to win the tournament so their exertions under the lights do not carry the extra heat of intense scrutiny.

The great carry a heavier burden. The grand slam winning triumvirate of Roger Federer (16 major titles), Rafael Nadal (10) and Novak Djokovic (four, and three of them this season) have questions they must answer. Andy Murray, the other member of the top eight players in the world, faces perhaps the most pressing inquiry as he seeks to leave the category of very good forever and irrefutably adopt the mantle of greatness.

For the Scot, of course, this leap can not be made at the O2 Arena. The world No.3 needs a grand slam victory to move him truly into the category where carping ends and celebration begins.

Yet this week can reinforce Murray’s belief that he is ready to take a step forward. Placed in the tougher group with Djokovic, Ferrer and Berdych, Murray will seek to confirm the favourable impression made by his three-title haul on the Asian swing.

The Scot has taken heart from overtaking Federer to become No.3 in the world rankings but knows the arithmetic of world tennis takes second place to the glory of winning a major. He will be anxious to go into his punishing month of training in Miami on the back of performances that suggest he can win the Australian Open early next year.

The question for Djokovic is somewhat more relaxed. He arrives in London with a doubt over his fitness, with back and shoulder injuries both troubling him in the second half of a season that has been spectacular for the Serb.

However, it will be fascinating to see how the world No.1 reacts when put under pressure at the O2. Will he decide that his three-major haul in a season is enough and that further triumph is unnecessary? Or will he give further evidence that he has changed a mindset that once was suspect and is playing to win at all costs?

The answer – win or lose – will give the tennis world an indication of just how determined Djokovic, at 24, is to dominate the sport for an era instead of a season.

Federer yesterday spoke to the heart of this matter. “When you get to world No.1 you get even hungrier and have even more appetite to stay there,” he said. “That in turn then takes up more energy and it drains you as you have to do a lot of other things which are associated with being the best in the world.”

Will Djokovic be energised or enervated?

In contrast, the question for Federer, now turned 30, is whether his two end of season titles constitute a renaissance and signal an imminent end to his 22-month drought of winning grand slams. The Swiss player, with the perversity of the true great, spent the first six months of the year auditioning for sporting obituaries only to march on London as a justifiable favourite.

Asked if he felt the pressure of being defending champion, Federer answered with his trademark facility: “I am used to it.” Indeed. He is seeking his sixth tour finals title which would be yet another personal record.

But what of Nadal and the questions hovering over his head? The Spaniard faces an important two weeks. He will lead Spain into the Davis Cup final against Argentina after the tour finals, so will the great competitor be diminished ever so slightly in London by such a demanding prospect?

More pertinently, how stands Nadal’s mindset and form? It is impossible to judge the latter given the Spaniard’s absence from the court. The former may constitute the most interesting inquiry in contemporary sport.

Nadal has been beaten in six consecutive finals by Djokovic and has admitted the Serb has become a psychological as well as professional problem. How badly has the Mallorcan been affected?

He was strenuous in his protestations yesterday that Djokovic did not dominate his thoughts.

“All my life I’ve worked for myself, to improve myself. I’m not working every day thinking about Novak. I’m working and thinking about what I need to do to keep improving, to be a better player. That’s what I’ve done all my career and what I want to keep doing,” he said.

“I can talk with Toni [his uncle and coach], I can talk with a lot of people, but at the end of the day what I have to do is work hard to keep improving. So that’s it. So Djokovic is not a goal for me. A goal is to be a better player than I was last year. Later we will see if that’s enough.”

It is an interesting question. The beginnings of an answer to this and so much more may just be articulated next week.