Roger Federer of Switzerland plays a return to Rafael Nadal of Spain during their round robin singles match at the ATP World Tour Finals, at the O2 arena in London, Tuesday, Nov. 22, 2011. (AP Photo/Kirsty Wigglesworth)

Associated Press
Roger Federer of Switzerland plays a return to Rafael Nadal of Spain during their round robin singles match at the ATP World Tour Finals, at the O2 arena in London, Tuesday, Nov. 22, 2011. (AP Photo/Kirsty Wigglesworth)
Roger Federer of Switzerland plays a return to Rafael Nadal of Spain during their round robin singles match at the ATP World Tour Finals, at the O2 arena in London, Tuesday, Nov. 22, 2011. (AP Photo/Kirsty Wigglesworth)
View Comments (0)