Two-time defending champion Novak Djokovic has been handed a favourable draw at the ATP Finals, while Roger Federer and Andy Murray will meet in the round-robin phase.
The top-seeded Djokovic, who won his 20th Masters title in Paris on Sunday, was placed in the same group with Australian Open champion Stan Wawrinka, US Open winner Marin Cilic and Tomas Berdych for the season-ending, eight-man tournament, which starts Sunday in London.
"Two successive titles in London in the last two years gave me reason to believe that I can do well," said Djokovic after winning in Paris, where he did not drop a set during the whole week.
The in-form Federer, meanwhile, is in Group B along with Murray and newcomers Kei Nishikori and Milos Raonic.
Djokovic, this year's Wimbledon champion, is unbeaten on indoors courts the past two years and is vying with Federer for the year-end No.1 ranking.
The Serb extended his lead over the 17-time grand slam champion to 1,310 points as he bids to finish the year on top for the third time.
Federer's quarter-finals loss in Paris against Raonic has hampered his bid to overtake Djokovic in London, where a potential 1,500 points are up for grabs.
Rafael Nadal is skipping the tournament to have appendix surgery.
