Roger Federer of Switzerland in action against Marcel Granollers of Spain during their second round match for the French Open tennis tournament at Roland Garros in Paris, France, 27 May 2015. EPA/ROBERT GHEMENT

Roger Federer of Switzerland plays Novak Djokovic of Serbia in the men’s final of the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 12 July 2015. EPA/FACUNDO ARRIZABALAGA

Roger Federer of Switzerland serves to Mikhail Youzhny of Russia during the first round of the Dubai Duty Free Tennis ATP Championships in Dubai, United Arab Emirates, 23 February 2015. EPA/ALI HAIDER

Roger Federer of Switzerland during the Mens final against Milos Raonic of Canada at the Brisbane International Tennis Tournament in Brisbane, Australia, Sunday, January 11, 2015. EPA/DAVE HUNT

Roger Federer of Switzerland hits a return to Marin Cilic of Croatia during their semifinals round match on the thirteenth day of the 2014 US Open Tennis Championship at the USTA National Tennis Center in Flushing Meadows, New York, USA, 06 September 2014. The US Open runs through 08 September, a 15-day schedule. EPA/JUSTIN LANE

Swiss tennis player Roger Federer celebrates after winning the final match against Colombia’s Alejandro Falla at the ATP tournament in Halle (Westphalia), Germany, 15 June 2014. Federer won the final in straight sets EPA/OLIVER KRATO