London - Novak Djokovic insists he isn't concerned about winning the race to finish 2013 above Rafael Nadal at the top of the world rankings.
Djokovic goes into the season-ending ATP World Tour Finals at London's O2 Arena still in with a chance of snatching pole position from current world number one Nadal.
When Nadal beat Djokovic to win the US Open, it seemed the Spaniard was certain to take top spot at the end of the year.
But the world number two has won all of his 17 matches since New York, with his third straight title coming on Sunday at the Paris Masters, and he still has a slim chance of overtaking Nadal depending on their results in London this week.
For that to happen, the Serb must retain the Tour Finals title he won for the second time last year and then gain maximum points in the Davis Cup final against the Czech Republic, while Nadal would have to fail to win two of his three group matches in London.
But for Djokovic, who begins his Tour Finals campaign against Roger Federer on Tuesday, the most important thing is that he is again playing at the level that made such an unstoppable force 2011 and 2012.
"It doesn't make sense for me to get into the number one calculations," Djokovic said.
"What is important for me is that I know winning three tournaments in a row, 17 matches in a row, gives me a lot of confidence coming into this week and the closing weeks of the season and opening up the next season also.
"I'm building something for what's coming up and, if I finish number one, that would be an incredible achievement and I would be very happy but of course it's not at the top of my priority list right now.
"I know the rankings will follow if I have good results."
After winning the Australian Open in January, Djokovic has suffered painful defeats in the semi-finals of the French Open and the Wimbledon and US Open finals.
Those losses caused some to question whether the 26-year-old was hungry enough after winning five Grand Slam titles from January 2011 to January 2013, and he conceded he may have lost a little consistency for a while.
"I don't want to sound arrogant but I felt the summer was too much up and down. I could have had a little bit more consistency," Djokovic said.
"But after the US Open I managed to feel well on the court again, to connect with myself, to enjoy it and to get the right stability and consistency throughout all the matches.
"Results have helped of course to build that confidence and now I'm feeling good about myself on the court."