David Ferrer of Spain hits a return to Juan Martin del Potro of Argentina during their men's quarter-final tennis match at the Wimbledon Tennis Championships, in London July 3, 2013. [Photo/Agencies]
Juan Martin del Potro of Argentina hits a return during his men's quarter-final tennis match against David Ferrer of Spain at the Wimbledon Tennis Championships, in London July 3, 2013. [Photo/Agencies]