LONDON, ENGLAND - JUNE 30: Novak Djokovic of Serbia practices before the Championships at the All England Lawn Tennis and Croquet Club in Wimbledon on June 30, 2018 in London, England. (Photo by TPN/Getty Images)
LONDON, ENGLAND - JUNE 30: Novak Djokovic of Serbia practices before the Championships at the All England Lawn Tennis and Croquet Club in Wimbledon on June 30, 2018 in London, England. (Photo by TPN/Getty Images)