Andy Murray will play Czech Tomas Berdych in his opening match after being handed a difficult draw at the ATP World Tour Finals in London.
The Briton was placed in Group A, along with world number one Novak Djokovic, world number six Berdych and world number seven Jo-Wilfried Tsonga.
Murray plays Berdych at 13:45 GMT on Monday, before Djokovic meets Tsonga.
Roger Federer, David Ferrer, Juan Martin del Potro and Janko Tipsarevic have been drawn in Group B.
The top two players from each group progress to the semi-finals at the season-ending tournament.
Murray has a losing record against Berdych, the Czech having won four of their seven matches, but the Scot prevailed over four sets in the US Open semi-finals in September.
He went on to win his first Grand Slam title by beating Djokovic in the final, but the Serb still holds a 9-7 lead in matches between the two and saved match points on his way to defeating the Murray in Shanghai last month.
