...Nikolay Davydenko of Russia returns the ball during the men's singles round robin match against Robin Soderling of Sweden during the Barclays ATP World Tour Finals at the O2 Arena on November 27...

Robin Soderling of Sweden plays against Rafael Nadal of Spain in a Singles match during the Barclays ATP...

...NOVEMBER 23: Rafael Nadal of Spain reacts after the men's singles first round match against Robin Soderling of Sweden during the Barclays ATP World Tour Finals at the O2 Arena on November 23...

LONDON, ENGLAND - NOVEMBER 23: Robin Soderling of Sweden returns the ball during the men's singles first round match against Rafael Nadal...

Novak Djokovic of Serbia returns the ball to Robin Soderling of Sweden during the BNP Masters indoor tennis tournament in Paris, Friday, Nov. 13, 2009. Djokovic...

BEIJING - OCTOBER 10: Novac Djokovic of Serbia serves against Robin Soderling of Sweden in their semi-finals during day nine of the 2009 China Open at the...

BEIJING - OCTOBER 10: Novac Djokovic of Serbia returns a shot to Robin Soderling of Sweden in their semi-finals during day nine of the 2009 China Open at the...

NEW YORK - SEPTEMBER 05: Sam Querrey of the United States serves to Robin Soderling of Sweden during day six of the 2009 U.S. Open at the USTA Billie Jean...

Swiss tennis player Roger Federer returns to Swedish player Robin Soderling during their quarterfinals match of the 2009 US Open at the USTA Billie Jean King National...

NEW YORK - SEPTEMBER 09: Roger Federer of Switzerland celebrates a point against Robin Soderling of Sweden during day ten of the 2009 U.S. Open at the USTA Billie Jean...

NEW YORK - SEPTEMBER 09: Roger Federer of Switzerland serves to Robin Soderling of Sweden during day ten of the 2009 U.S. Open at the USTA Billie Jean...

Swiss tennis player Roger Federer returns to Swedish player Robin Soderling during their quarterfinals match of the 2009 US Open at the USTA Billie Jean King National...

May 31, 2009; Paris, FRANCE; Rafael Nadal (ESP) reacts during his match against Robin Soderling (SWE) on day eight of the 2009 French Open at Roland Garros. Soderling defeated Nadal 6...

...HAMBURG, GERMANY - JULY 22: Robin Soderling of Sweden returns the ball during the match against Fabio Fognini of Italy during day three...

...poses with the trophy as he celebrates victory during the Men's Singles Final match against Robin Soderling of Sweden on day fifteen of the French Open at Roland Garros on June 7, 2009...