Old foes Rafa Nadal and Roger Federer will meet in the group stage of the ATP World Tour Finals starting in London Sunday, while world No. 1 Novak Djokovic will clash with No. 3 Andy Murray. The round-robin competition which ends the men's tennis season is made up of two groups of four with the top two from each pool going through to the semifinals. Defending champion Federer has not won a Grand Slam singles title this year for the first time since 2002 but has bounced back to form with triumphs in his last two tournaments including last week's Paris Masters. “Anyone can beat anyone,” said Federer before the draw ceremony in London. “I'm really looking forward to it. It's a strong year.” Nadal and Federer are joined in Group B by Frenchman Jo-Wilfried Tsonga, who beat Federer in this year's Wimbledon quarterfinals but lost to the Swiss in Sunday's Paris final. American Mardy Fish completes the pool despite being troubled with a hamstring strain. Spaniard Nadal, who beat long-time rival Federer in the French Open final in June, missed the Paris Masters in order to focus on the World Tour Finals — which includes the eight best players this year. Djokovic, who has enjoyed a scorching year including winning the Australian Open, Wimbledon and US Open, also pulled out of the Paris Masters because of a sore shoulder but should be fit for the week-long London showpiece. The Serbian has been drawn in Group A alongside Briton Murray, Spaniard David Ferrer and Czech Tomas Berdych. Murray's 17-match winning streak was ended by Berdych in the Paris quarter-finals last week. Murray for funding crackdown Murray has urged British tennis chiefs to slash the amount of funding given to players to let more of them earn their own money. The Scot, speaking ahead of the start of the ATP World Tour Finals in London, cited the example of tennis powerhouse Spain as one Britain ought to follow in its quest for success. Murray, who joined a tennis academy in Spain at the age of 15, told the Daily Mail: “Do you know that in Spain, at 18, your funding stops? “From there, you get nothing that you cannot earn for yourself. We're funding guys to (the age of) 27, 28 — while in the most successful tennis nation in the world you're basically on your own. Maybe there's something in that. “When I went to Spain, from the best players to the worst players we were all taught the same way, all given the same drills,” the 24-year-old added. “They had a structure and they stuck to it. Go to our national center and you've got 10 different nationalities all coaching a different way. If we don't get the results straight away, we panic and change direction.” Despite Britain's governing Lawn Tennis Association receiving millions of pounds each year from the profits of the Wimbledon Championships, no British man has won a Grand Slam singles title since Fred Perry in 1936.