Dustin Brown of Germany in action against Yen-Hsun Lu of Taiwan during their first round match for the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 30 June 2015. EPA/FACUNDO ARRIZABALAGA

Roger Federer of Switzerland returns to Damir Zumhur of Bosnia in their first round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 30 June 2015. EPA/ANDY RAIN

Jo-Wilfried Tsonga of France in action against Gilles Muller of Luxembourg during their first round match for the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 30 June 2015. EPA/FACUNDO ARRIZABALAGA

Petra Kvitova of the Czech Republic serves to Kiki Bertens of the Netherlands in their first round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 30 June 2015. EPA/ANDY RAIN

Rafael Nadal of Spain in action against Thomaz Bellucci of Brazil during their first round match for the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 30 June 2015. EPA/GERRY PENNY