Jelena Dokic of Australia serves to Anna Chakvetadze of Russia during their women's singles match at the Australian Open tennis tournament in Melbourne January 17, 2012. REUTERS/Mark Blinch (AUSTRALIA - Tags: SPORT TENNIS)

Jelena Dokic of Australia serves to Anna Chakvetadze of Russia during their women's singles match at the Australian Open tennis tournament in Melbourne January 17, 2012. REUTERS/Mark Blinch (AUSTRALIA - Tags: SPORT TENNIS)

Maria Sharapova of Russia reacts after defeating Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Maria Sharapova of Russia reacts after defeating Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Maria Sharapova of Russia reacts after defeating Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia hits a return to Maria Sharapova of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Maria Sharapova of Russia hits a return to Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Maria Sharapova of Russia reacts during her match against Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Maria Sharapova of Russia reacts during her match against Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Maria Sharapova of Russia waits to receive a serve from Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Sasha Vujacic of the New Jersey Nets, the boyfriend of Maria Sharapova of Russia, watches the match between Sharapova and Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Maria Sharapova of Russia serves to Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia touches her hair during her match against Maria Sharapova of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Maria Sharapova of Russia hits a return to Anna Chakvetadze of Russia at the Wimbledon tennis championships in London June 21, 2011. REUTERS/Stefan Wermuth (BRITAIN - Tags: SPORT TENNIS)

Caroline Wozniacki (back) of Denmark hugs Anna Chakvetadze of Russia after Chakvetadze retired from the match at the WTA Dubai Tennis Championships February 16, 2011. Chakvetadze had been suffering from a stomach illness for the last 24 hours and fell down during the eighth game of the second set. REUTERS/Jumana El-Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Caroline Wozniacki of Denmark returns a shot to Anna Chakvetadze of Russia during their match at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Caroline Wozniacki of Denmark throws her racket during her match against Anna Chakvetadze of Russia at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Jumana El-Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia returns a shot to Caroline Wozniacki of Denmark during their match at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia returns a shot to Caroline Wozniacki of Denmark during their match at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Caroline Wozniacki of Denmark returns a shot to Anna Chakvetadze of Russia during their match at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Caroline Wozniacki of Denmark hits a return to Anna Chakvetadze of Russia during their match at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Jumana El-Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia serves the ball to Caroline Wozniacki of Denmark during their match at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia gets up to continue after she fell over during her match against Caroline Wozniacki of Denmark at the WTA Dubai Tennis Championships February 16, 2011. Chakvetadze had been suffering from a stomach illness for the last 24 hours and fell down during the eighth game of the second set. REUTERS/Jumana El-Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

A medic speaks to Anna Chakvetadze of Russia after she fell over during her match against Caroline Wozniacki of Denmark at the WTA Dubai Tennis Championships February 16, 2011. Chakvetadze had been suffering from a stomach illness for the last 24 hours and fell down during the eighth game of the second set. REUTERS/Jumana El-Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

A medic speaks to Anna Chakvetadze of Russia after she fell over during her match against Caroline Wozniacki of Denmark at the WTA Dubai Tennis Championships February 16, 2011. Chakvetadze had been suffering from a stomach illness for the last 24 hours and fell down during the eighth game of the second set. REUTERS/Jumana El-Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia hits a return to Caroline Wozniacki of Denmark during their match at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Jumana El-Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Caroline Wozniacki of Denmark hits a return to Anna Chakvetadze of Russia during their match at the WTA Dubai Tennis Championships February 16, 2011. REUTERS/Jumana El-Heloueh (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Daniela Hantuchova of Slovakia returns a shot to Anna Chakvetadze of Russia during their match at the WTA Dubai Tennis Championships February 15, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Daniela Hantuchova of Slovakia serves the ball to Anna Chakvetadze of Russia during their match at the WTA Dubai Tennis Championships February 15, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia returns a shot to Daniela Hantuchova of Slovakia during their match at the WTA Dubai Tennis Championships February 15, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia serves to Daniela Hantuchova of Slovakia during their match at the WTA Dubai Tennis Championships February 15, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia returns a shot to Daniela Hantuchova of Slovakia during their match at the WTA Dubai Tennis Championships February 15, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Daniela Hantuchova of Slovakia eyes the ball before returning a shot to Anna Chakvetadze of Russia during their match at the WTA Dubai Tennis Championships February 15, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia returns a shot to Daniela Hantuchova of Slovakia during their match at the WTA Dubai Tennis Championships February 15, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Daniela Hantuchova of Slovakia eyes the ball before returning a shot to Anna Chakvetadze of Russia during their match at the WTA Dubai Tennis Championships February 15, 2011. REUTERS/Saleh Salem (UNITED ARAB EMIRATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia reacts during her match against Petra Kvitova of the Czech Republic at the Australian Open tennis tournament in Melbourne January 20, 2011. REUTERS/Daniel Munoz (AUSTRALIA - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia hits a return to Petra Kvitova of the Czech Republic during their match at the Australian Open tennis tournament in Melbourne January 20, 2011. REUTERS/Daniel Munoz (AUSTRALIA - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia hits a return to Petra Kvitova of the Czech Republic during their match at the Australian Open tennis tournament in Melbourne January 20, 2011. REUTERS/Daniel Munoz (AUSTRALIA - Tags: SPORT TENNIS)

Petra Kvitova of the Czech Republic hits a return to Anna Chakvetadze of Russia during their match at the Australian Open tennis tournament in Melbourne January 20, 2011. REUTERS/Daniel Munoz (AUSTRALIA - Tags: SPORT TENNIS)

Petra Kvitova of the Czech Republic hits a return to Anna Chakvetadze of Russia during their match at the Australian Open tennis tournament in Melbourne January 20, 2011. REUTERS/Daniel Munoz (AUSTRALIA - Tags: SPORT TENNIS)

Serena Williams of the U.S. serves to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Serena Williams of the U.S. hits a return to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Serena Williams of the U.S. runs to hit a return to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Serena Williams of the U.S. prepares to serve to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: ENTERTAINMENT FASHION SOCIETY SPORT SPORT TENNIS)

Serena Williams of the U.S. hits a return to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Serena Williams of the U.S. hits a return to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Serena Williams of the U.S. curtseys as she celebrates defeating Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Serena Williams of the U.S. runs to hit a return to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Serena Williams of the U.S. hits a return to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Serena Williams of the U.S. serves to Russia's Anna Chakvetadze at the 2010 Wimbledon tennis championships in London, June 24, 2010. REUTERS/Phil Noble (BRITAIN - Tags: SPORT TENNIS)

Russia's Anna Chakvetadze hits a return to Japan's Kimiko Date Krumm during their Sony Ericsson Open tennis tournament match in Key Biscayne, Florida, March 24, 2010. REUTERS/Andrew Innerarity (UNITED STATES - Tags: SPORT TENNIS)

Russia's Anna Chakvetadze hits a return to Japan's Kimiko Date Krumm during their Sony Ericsson Open tennis tournament match in Key Biscayne, Florida, March 24, 2010. REUTERS/Andrew Innerarity (UNITED STATES - Tags: SPORT TENNIS)

Japan's Kimiko Date Krumm returns a shot to Russia's Anna Chakvetadze during their Sony Ericsson Open tennis tournament match in Key Biscayne, Florida, March 24, 2010. REUTERS/Andrew Innerarity (UNITED STATES - Tags: SPORT TENNIS)

Japan's Kimiko Date Krumm signs autographs upon leaving the court after defeating Russia's Anna Chakvetadze at the Sony Ericsson Open tennis tournament in Key Biscayne, Florida, March 24, 2010. REUTERS/Andrew Innerarity (UNITED STATES - Tags: SPORT TENNIS)

Japan's Kimiko Date Krumm reacts to a point she won in the third set against Russia's Anna Chakvetadze during their Sony Ericsson Open tennis tournament match in Key Biscayne, Florida, March 24, 2010. REUTERS/Andrew Innerarity (UNITED STATES - Tags: SPORT TENNIS)

Japan's Kimiko Date Krumm returns a shot to Russia's Anna Chakvetadze during their Sony Ericsson Open tennis tournament in Key Biscayne, Florida, March 24, 2010. REUTERS/Andrew Innerarity (UNITED STATES - Tags: SPORT TENNIS)

Agnieszka Radwanska of Poland tosses the ball to serve against Anna Chakvetadze of Russia during their match at the Indian Wells WTA tennis tournament in Indian Wells, California, March 12, 2010. REUTERS/Danny Moloshok (UNITED STATES - Tags: SPORT TENNIS)

Agnieszka Radwanska of Poland tosses the ball to serve against Anna Chakvetadze of Russia during their match at the Indian Wells WTA tennis tournament in Indian Wells, California, March 12, 2010. REUTERS/Danny Moloshok (UNITED STATES - Tags: SPORT TENNIS)

Agnieszka Radwanska of Poland returns a shot against Anna Chakvetadze of Russia during their match at the Indian Wells WTA tennis tournament in Indian Wells, California, March 12, 2010. REUTERS/Danny Moloshok (UNITED STATES - Tags: SPORT TENNIS)

Anna Chakvetadze of Russia returns a shot against Agnieszka Radwanska of Poland during their match at the Indian Wells WTA tennis tournament in Indian Wells, California, March 12, 2010. REUTERS/Danny Moloshok (UNITED STATES)