|ATP World Tour Finals|
|Venue: O2 Arena, London Date: 13-20 November|
|Coverage: Live coverage on BBC Two, BBC Radio 5 live sports extra & BBC Sport website, tablets, mobiles and app. Click here for details.|
Andy Murray expects Novak Djokovic to "start playing his best tennis again" soon as they prepare to compete for the world number one spot.
However, the Serb has won the past four titles at London's O2 Arena.
"There's no reason to think he won't have a really good tournament," said 29-year-old Murray.
Djokovic's form has been the subject of much debate in recent months, with just one tournament win since June and early exits at Wimbledon and the Olympics.
But Murray said: "Before then he'd been playing great, so for him not play his best tennis for a couple of months, I'm sure it's not too much to worry about.
"I'd imagine shortly he'll be back to playing his best tennis."
Djokovic, 29, will open against Austria's Dominic Thiem on Sunday, before Murray plays Croatia's Marin Cilic in his first group match on Monday.
The Scot has lost just three matches since he last played Djokovic in June, when the Serb completed the career Grand Slam by winning the French Open.
Murray's spectacular run of form culminated in a first Paris Masters win on Sunday and the number one ranking for the first time on Monday.
"It feels good, obviously, but I don't feel any different this week than I did the week before," he said.
"Maybe when you step on the court you have a little bit more confidence and feel a little bit better about yourself when you're hitting balls. But I didn't feel much different when I woke up on Monday morning. I felt just the same."
On his indifferent form, Djokovic said: "The high standard of results and success that I've had the last couple of years probably has taken its toll.
"I didn't get to recover as fast after the French Open to be ready to compete on the highest level after that.
"All in all it was a very good year that I'm proud of. I'm here in London to try to crown this year with the best possible result."
|ATP World Tour Finals group stage|
|John McEnroe Group||Ivan Lendl Group|
|1. Andy Murray (GB)||2. Novak Djokovic (Ser)|
|3. Stan Wawrinka (Swi)||4. Milos Raonic (Can)|
|5. Kei Nishikori (Jpn)||6. Gael Monfils (Fra)|
|7. Marin Cilic (Cro)||8. Dominic Thiem (Aut)|
Murray's record in the ATP World Tour Finals
Appearances: Seven (eight qualifications)
Finals: None Semi-finals: Three Win-loss record: 11-11
2008: Murray qualified for the year-end tournament - then known as the Masters Cup and held in Shanghai - for the first time. He beat Andy Roddick, Gilles Simon and Roger Federer, but lost to Nikolay Davydenko in the semi-finals.
2009: He won two of his three group matches but Juan Martin del Potro's win over Federer saw the Argentine advance at Murray's expense.
2010: Wins over Robin Soderling and David Ferrer saw Murray advance to the semi-finals, despite a straight-sets defeat by Federer in his second match. He lost a hard-fought semi-final featuring two tie-breaks to Rafael Nadal.
2011: Murray lost his opening match in London to Ferrer before withdrawing from the tournament, his place going to Serbia's Janko Tipsarevic.
2012: The last time Murray reached the knockout stages of the tournament. The newly-crowned US Open champion beat Tomas Berdych and Jo-Wilfried Tsonga in his group, either side of a defeat to Djokovic, but lost to Federer in the semi-final.
2013: Murray's first Wimbledon title was the highlight of his season as he qualified as the fourth-ranked player, but he withdrew before the tournament to have surgery on a back problem and was replaced by Richard Gasquet.
2014: Defeat to this year's group-stage opponent Kei Nishikori and a 6-0 6-1 hammering by Federer saw Murray eliminated before the semi-finals.
2015: Murray opened his campaign with victory over Ferrer, but defeats to Nadal and Stan Wawrinka - another of this year's opponents - saw him eliminated at the group stage.