Serena Williams of the U.S. reacts during her women's semi-final match against Timea Bacsinszky of Switzerland at the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 4, 2015. REUTERS/Gonzalo Fuentes TPX IMAGES OF THE DAY

Lucie Safarova of the Czech Republic celebrates after defeating Ana Ivanovic of Serbia during their women's semi-final match at the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 4, 2015. REUTERS/Pascal Rossignol TPX IMAGES OF THE DAY

Timea Bacsinszky of Switzerland reacts during her women's semi-final match against Serena Williams of the U.S. at the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 4, 2015. REUTERS/Gonzalo Fuentes

Rafael Nadal of Spain returns the ball to Novak Djokovic of Serbia during their men's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 3, 2015. REUTERS/Vincent Kessler 

Serena Williams of the U.S. returns the ball to Sara Errani of Italy during their women's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 3, 2015. REUTERS/Jean-Paul Pelissier 

Tennis - French Open - Roland Garros, Paris, France - 3/6/15Women's Singles - Switzerland's Timea Bacsinszky celebrates winning her quarter final matchAction Images via Reuters / Jason CairnduffLivepic 

Rafael Nadal of Spain serves to Novak Djokovic of Serbia during their men's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 3, 2015. REUTERS/Vincent Kessler 

David Ferrer of Spain returns the ball to Andy Murray of Britain during their men's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 3, 2015. REUTERS/Pascal Rossignol 

Tennis - French Open - Roland Garros, Paris, France - 3/6/15Men's Singles - Spain's David Ferrer in action during the quarter finalAction Images via Reuters / Jason Cairnduff 

Tennis - French Open - Roland Garros, Paris, France - 3/6/15Men's Singles - Serbia's Novak Djokovicin action during the quarter finalAction Images via Reuters / Jason Cairnduff 

Lucie Safarova of the Czech Republic celebrates after defeating Garbine Muguruza of Spain during their women's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 2, 2015. REUTERS/Vincent Kessler 

Jo-Wilfried Tsonga of France returns the ball to Kei Nishikori of Japan during their men's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 2, 2015. REUTERS/Jean-Paul Pelissier 

Roger Federer of Switzerland leaves the court after being defeated by his compatriot Stan Wawrinka during their men's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 2, 2015. REUTERS/Vincent Kessler 

Kei Nishikori of Japan returns the ball to Jo-Wilfried Tsonga of France during their men's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 2, 2015. REUTERS/Jean-Paul Pelissier 

Jo-Wilfried Tsonga of France celebrates after defeating Kei Nishikori of Japan during their men's quarter-final match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 2, 2015. REUTERS/Jean-Paul Pelissier 

Tennis - French Open - Roland Garros, Paris, France - 2/6/15Men's Singles - France's Jo Wilfried Tsonga celebrates winning his quarter final matchAction Images via Reuters / Jason Cairnduff 

Novak Djokovic of Serbia prepares to serve to Richard Gasquet of France during their men's singles match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 1, 2015. REUTERS/Gonzalo Fuentes 

Jeremy Chardy of France returns the ball to Andy Murray of Britain during their men's singles match during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 1, 2015. REUTERS/Vincent Kessler 

Andy Murray of Britain reacts during his men's singles match against Jeremy Chardy of France during the French Open tennis tournament at the Roland Garros stadium in Paris, France, June 1, 2015. REUTERS/Vincent Kessler 

Alize Cornet of France argues with the referee during the women's singles match against Elina Svitolina of Ukraine at the French Open tennis tournament at the Roland Garros stadium in Paris, France, May 31, 2015. REUTERS/Pascal Rossignol 

Pablo Andujar of Spain plays a shot to Jo-Wilfried Tsonga of France during their men's singles match at the French Open tennis tournament at the Roland Garros stadium in Paris, France, May 29, 2015. REUTERS/Gonzalo Fuentes 

Mirjana Lucic-Baroni of Croatia celebrates after beating Simona Halep of Romania during their women's singles match at the French Open tennis tournament at the Roland Garros stadium in Paris, France, May 27, 2015. REUTERS/Vincent Kessler 

Caroline Wozniacki of Denmark plays a shot to Karin Knapp of Italy during their women's singles match at the French Open tennis tournament at the Roland Garros stadium in Paris, France, May 26, 2015. REUTERS/Gonzalo Fuentes 

The shoes of Rafael Nadal of Spain are seen as he jumps to serve to Quentin Halys of France during their men's singles match at the French Open tennis tournament at the Roland Garros stadium in Paris, France, May 26, 2015. REUTERS/Vincent Kessler 

Petra Martic of Croatia plays a shot to Garbine Muguruza of Spain during the women's singles match at the French Open tennis tournament at the Roland Garros stadium in Paris, France, May 24, 2015. REUTERS/Gonzalo Fuentes