Andy Murray of Great Britain returns to Liam Broady of Great Britain during their first round match at Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 28 June 2016 EPA/ANDY RAIN

Novak Djokovic of Serbia returns to Britain’s James Ward in their first round match of the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 27 June 2016. EPA/GERRY PENNY

Nick Kyrgios of Australia returns to Radek Stepanek of the Czech Republic during their first round match of the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 28 June 2016. EPA/HANNAH MCKAY

Petra Kvitova of Czech Republic serves to Sorena Cirstea of Romania during their second round match during the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 29 June 2016 EPA/ANDY RAIN

Dustin Brown of Germany during his second round match against Dusan Lajovic of Serbia at the Wimbledon Championships, All England Lawn Tennis Club, in London, Britain, 28 June 2016 EPA/ANDY RAIN

Agnieszka Radwanska of Poland returns to Kateryna Kozlova of Ukraine during their first round match of the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 29 June 2016. EPA/FACUNDO ARRIZABALAGA