ATP World Tour Finals
Venue: O2 Arena, London Dates: 22-29 November
Coverage: BBC Two and streamed on BBC Sport website, 22/28/29 November, 1400 GMT; every match live on 5 live/5 live sports extra; live text commentaries on BBC Sport website; live coverage every day on Sky Sports
Full details of BBC TV coverage
Roddick also had to pull out of last year's finale with injury
World number six Andy Roddick has withdrawn from the forthcoming World Tour Finals in London with injury.
The 27-year-old American, who lost an epic Wimbledon men's singles final in the capital in July, has been sidelined for five weeks with a knee problem.
Sweden's Robin Soderling will replace him at the end-of-season finale, which begins on Sunday.
Roddick said: "I'm really disappointed. I love playing in London and I've heard so many good things about the venue."
Wimbledon champion Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray are among those taking part in the tournament at the O2 Arena.
Juan Martin del Potro, Nikolay Davydenko and Fernando Verdasco complete the line-up.
Injury also forced Roddick to pull out of last year's event, which was staged in China, after losing his opening match to Murray.
Roddick picked up his latest injury in last month's Shanghai Masters, when he had to pull out of a second-round match against Stanislaus Wawrinka.
The American added: " I have not fully recovered from my knee injury and I won't be able to compete. One of my goals in 2010 will be to qualify for this event again."