Juan Martin del Potro of Argentina reacts to his play against Dmitry Tursunov of Russia during their quarterfinal match at the men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 16, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Juan Martin del Potro of Argentina waves to the crowd after defeating Dmitry Tursunov of Russia in three sets in their quarterfinal match at the men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 16, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Juan Martin Del Potro of Argentina hits a return ball to Dmitry Tursunov of Russia during their quarter final round match at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 16, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS TPX IMAGES OF THE DAY) 

Dmitry Tursunov of Russia hits a return ball to Juan Martin Del Potro of Argentina during their quarter final round match at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 16, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia reacts to his play against Juan Martin Del Potro of Argentina during their quarter final round match at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 16, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Juan Martin Del Potro of Argentina hits a return ball to Dmitry Tursunov of Russia during their quarter final round match at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 16, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Juan Martin Del Potro of Argentina hits a return ball to Dmitry Tursunov of Russia during their quarter final round match at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 16, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Juan Martin Del Potro of Argentina hits a return ball to Dmitry Tursunov of Russia during their quarter final round match at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 16, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia hits a return ball to David Ferrer of Spain at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 15, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia serves to David Ferrer of Spain at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 15, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia reacts to a call by the umpire during his match against David Ferrer of Spain at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 15, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

David Ferrer of Spain serves to Dmitry Tursunov of Russia at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 15, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

David Ferrer of Spain hits a return ball to Dmitry Tursunov of Russia at the Men's Cincinnati Open tennis tournament in Cincinnati, Ohio August 15, 2013. REUTERS/John Sommers II (UNITED STATES - Tags: SPORT TENNIS) 

Tommy Haas of Germany celebrates after defeating Dmitry Tursunov of Russia in their men's singles tennis match at the Wimbledon Tennis Championships, in London June 25, 2013. REUTERS/Suzanne Plunkett (BRITAIN - Tags: SPORT TENNIS)

Tommy Haas of Germany hits a return to Dmitry Tursunov of Russia in their men's singles tennis match at the Wimbledon Tennis Championships, in London June 25, 2013. REUTERS/Suzanne Plunkett (BRITAIN - Tags: SPORT TENNIS)

Tomas Berdych of Czech Republic hits a return to Dmitry Tursunov of Russia during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Tomas Berdych of Czech Republic reacts after hitting a return to Dmitry Tursunov of Russia during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Tomas Berdych of Czech Republic hits a return to Dmitry Tursunov of Russia during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Jumana El Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Tomas Berdych of the Czech Republic serves to Dmitry Tursunov of Russia during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Jumana El Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Tomas Berdych of the Czech Republic reacts after winning his men's singles quarter-final match against Dmitry Tursunov of Russia during the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Jumana El Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia hits a return to Tomas Berdych of the Czech Republic during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Tomas Berdych of the Czech Republic reacts after hitting a return to Dmitry Tursunov of Russia during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia hits a return to Tomas Berdych of Czech Republic during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia hits a return to Tomas Berdych of Czech Republic during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia hits a return to Tomas Berdych of the Czech Republic during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Tomas Berdych of Czech Republic hits a return to Dmitry Tursunov of Russia during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Tomas Berdych of Czech Republic serves to Dmitry Tursunov of Russia during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Tomas Berdych of the Czech Republic hits a return to Dmitry Tursunov of Russia during their men's singles quarter-final match at the ATP Dubai Tennis Championships February 28, 2013. REUTERS/Ahmed Jadallah (UNITED ARAB EMIRATES - Tags: SPORT TENNIS) 

Marcos Baghdatis of Cyprus returns a shot to Dmitry Tursunov of Russia during their men's singles quarter-finals match at the Japan Open tennis championships in Tokyo, October 5, 2012. REUTERS/Yuriko Nakao (JAPAN - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia returns a shot to Marcos Baghdatis of Cyprus during their men's singles quarter-finals match at the Japan Open tennis championships in Tokyo, October 5, 2012. REUTERS/Yuriko Nakao (JAPAN - Tags: SPORT TENNIS) 

Marcos Baghdatis of Cyprus celebrates his win over Dmitry Tursunov of Russia after their men's singles quarter-finals match at the Japan Open tennis championships in Tokyo, October 5, 2012. REUTERS/Yuriko Nakao (JAPAN - Tags: SPORT TENNIS) 

Marcos Baghdatis of Cyprus celebrates his win over Dmitry Tursunov of Russia after their men's singles quarter-finals match at the Japan Open tennis championships in Tokyo, October 5, 2012. REUTERS/Yuriko Nakao (JAPAN - Tags: SPORT TENNIS) 

Marcos Baghdatis of Cyprus returns a shot to Dmitry Tursunov of Russia during their men's singles quarter-finals match at the Japan Open tennis championships in Tokyo, October 5, 2012. REUTERS/Yuriko Nakao (JAPAN - Tags: SPORT TENNIS) 

Dmitry Tursunov of Russia reacts after missing a shot against Marcos Baghdatis of Cyprus during their men's singles quarter-finals match at the Japan Open tennis championships in Tokyo, October 5, 2012. REUTERS/Yuriko Nakao (JAPAN - Tags: SPORT TENNIS) 

Marcos Baghdatis of Cyprus celebrates his win over Dmitry Tursunov of Russia after their men's singles quarter-finals match at the Japan Open tennis championships in Tokyo, October 5, 2012. REUTERS/Yuriko Nakao (JAPAN - Tags: SPORT TENNIS) 

Spain's Feliciano Lopez returns to Russia's Dmitry Tursunov in their men's singles tennis match at the All England Lawn Tennis Club during the London 2012 Olympics Games July 30, 2012. REUTERS/Stefan Wermuth (BRITAIN - Tags: OLYMPICS SPORT TENNIS)

Russia's Dmitry Tursunov returns to Spain's Feliciano Lopez in their men's singles tennis match at the All England Lawn Tennis Club during the London 2012 Olympics Games July 30, 2012. REUTERS/Stefan Wermuth (BRITAIN - Tags: OLYMPICS SPORT TENNIS)

Spain's Feliciano Lopez returns to Russia's Dmitry Tursunov in their men's singles tennis match at the All England Lawn Tennis Club during the London 2012 Olympics Games July 30, 2012. REUTERS/Stefan Wermuth (BRITAIN - Tags: OLYMPICS SPORT TENNIS)

Julien Benneteau of France returns the ball to Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France returns the ball to Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Dmitry Tursunov of Russia (L) reacts next to a ball boy during his match against Julien Benneteau of France during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Dmitry Tursunov of Russia returns the ball to Julien Benneteau of France during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Dmitry Tursunov of Russia returns the ball to Julien Benneteau of France during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Dmitry Tursunov of Russia reacts during his match against Julien Benneteau of France during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Dmitry Tursunov of Russia returns the ball to Julien Benneteau of France during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Dmitry Tursunov of Russia reacts during his match against Julien Benneteau of France during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France returns the ball to Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France returns the ball to Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France waves after winning his match against Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France waves after winning his match against Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France waves after winning his match against Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France waves after winning his match against Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France reacts after winning his match against Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Julien Benneteau of France reacts after winning his match against Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 31, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Go Soeda of Japan returns the ball to Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 29, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Go Soeda of Japan returns the ball to Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 29, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Go Soeda of Japan returns the ball to Dmitry Tursunov of Russia during the French Open tennis tournament at the Roland Garros stadium in Paris May 29, 2012. REUTERS/Nir Elias (FRANCE - Tags: SPORT TENNIS)

Dmitry Tursunov of Russia hits a return to Janko Tipsarevic of Serbia during their men's singles match at the Australian Open tennis tournament in Melbourne January 17, 2012. REUTERS/Vivek Prakash (AUSTRALIA - Tags: SPORT TENNIS)

Janko Tipsarevic of Serbia reacts during his men's singles match against Dmitry Tursunov of Russia at the Australian Open tennis tournament in Melbourne January 17, 2012. REUTERS/Vivek Prakash (AUSTRALIA - Tags: SPORT TENNIS)

Janko Tipsarevic of Serbia hits a return to Dmitry Tursunov of Russia during their men's singles match at the Australian Open tennis tournament in Melbourne January 17, 2012. REUTERS/Vivek Prakash (AUSTRALIA - Tags: SPORT TENNIS)