Switzerland's Roger Federer (R) shakes hands with Japan's Kei Nishikori (L) after Federer won their men's singles quarter-final match on day nine of the 2019 Wimbledon Championships at The All England Lawn Tennis Club in Wimbledon, southwest London, on July 10, 2019. (Photo by Daniel LEAL-OLIVAS / AFP) / RESTRICTED TO EDITORIAL USE        (Photo credit should read DANIEL LEAL-OLIVAS/AFP/Getty Images)