World number one Novak Djokovic has insisted that he will not put pressure on himself to win the ATP World Tour Finals in order to complete a successful season.
The 24-year-old will go up against Tomas Berdych, David Ferrer and British number one Andy Murray in Group A before reaching the knockout stages of the tournament.
"I don't feel obliged to win the tournament in order to make this season perfect but I will do my best to prepare and finish off the season in style," Sky Sports News quotes Djokovic as saying.
The Serbian has claimed three Grand Slams this year: the Australian Open, Wimbledon and the US Open.