Roger Federer of Switzerland hits a return during the men's singles quarterfinal match against Jo-Wilfried Tsonga of France on day 10 of the French Open tennis tournament at the Roland Garros stadium in Paris June 4, 2013. Roger Federer lost 0-3. (Xinhua/Gao Jing)

Roger Federer of Switzerland hits a return during the men's singles quarterfinal match against Jo-Wilfried Tsonga of France on day 10 of the French Open tennis tournament at the Roland Garros stadium in Paris June 4, 2013. Roger Federer lost 0-3. (Xinhua/Gao Jing)

Roger Federer of Switzerland hits a return during the men's singles quarterfinal match against Jo-Wilfried Tsonga of France on day 10 of the French Open tennis tournament at the Roland Garros stadium in Paris June 4, 2013. Roger Federer lost 0-3. (Xinhua/Gao Jing)

Roger Federer of Switzerland hits a return during the men's singles quarterfinal match against Jo-Wilfried Tsonga of France on day 10 of the French Open tennis tournament at the Roland Garros stadium in Paris June 4, 2013. Roger Federer lost 0-3. (Xinhua/Gao Jing)

Roger Federer of Switzerland reacts at the press conference after the men's singles quarterfinal match against Jo-Wilfried Tsonga of France on day 10 of the French Open tennis tournament at the Roland Garros stadium in Paris June 4, 2013. Roger Federer lost 0-3. (Xinhua/Gao Jing)