Serbia's Novak Djokovic lifts his trophy after defeating Switzerland's Roger Federer during the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (AP Photo/Ben Curtis)

Serbia's Novak Djokovic lifts the trophy after defeating Switzerland's Roger Federer in the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (AP Photo/Tim Ireland), APTOPIX

Serbia's Novak Djokovic kisses the trophy after defeating Switzerland's Roger Federer in the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (AP Photo/Tim Ireland), APTOPIX

Serbia's Novak Djokovic kisses the trophy after defeating Switzerland's Roger Federer in the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (AP Photo/Tim Ireland), APTOPIX

Kate, Duchess of Cambridge, left, stands as Serbia's Novak Djokovic holds the trophy after defeating Switzerland's Roger Federer in the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (AP Photo/Kirsty Wigglesworth), APTOPIX

Serbia's Novak Djokovic is presented with the winners trophy by Britain's Kate, Duchess of Cambridge after defeating Switzerland's Roger Federer during the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (Will Oliver/Pool Photo via AP)

Winner Serbia's Novak Djokovic and second placed Switzerland's Roger Federer, left, hold their trophies after the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (AP Photo/Ben Curtis), APTOPIX

Serbia's Novak Djokovic poses with his trophy after defeating Switzerland's Roger Federer in the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (AP Photo/Ben Curtis), APTOPIX

Britain's Kate, Duchess of Cambridge holds the winner's trophy before presenting it to Serbia's Novak Djokovic after he defeated Switzerland's Roger Federer during the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (Adrian Dennis/Pool Photo via AP)

Britain's Kate, Duchess of Cambridge holds the winner's trophy before presenting it to Serbia's Novak Djokovic after he defeated Switzerland's Roger Federer during the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (Adrian Dennis/Pool Photo via AP)

Serbia's Novak Djokovic kisses the trophy during the presentation after he defeated Switzerland's Roger Federer during the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (Laurence Griffiths/Pool Photo via AP), APTOPIX

Kate, Duchess of Cambridge presents the trophy to Serbia's Novak Djokovic after he defeated Switzerland's Roger Federer in the men's singles final match of the Wimbledon Tennis Championships in London, Sunday, July 14, 2019. (AP Photo/Tim Ireland)

Image licensed to i-Images Picture Agency. 14/07/2019. London, United Kingdom. The Duchess of Cambridge waits to present the Men's Singles Trophy to Novak Djokovic on the last day of the Wimbledon Tennis Championships in London. Picture by Stephen Lock / i-Images

Image licensed to i-Images Picture Agency. 14/07/2019. London, United Kingdom. The Duchess of Cambridge presents the Men's Singles Trophy to Novak Djokovic on the last day of the Wimbledon Tennis Championships in London. Picture by Stephen Lock / i-Images

Image licensed to i-Images Picture Agency. 14/07/2019. London, United Kingdom. The Duchess of Cambridge presents the Men's Singles Trophy to Novak Djokovic on the last day of the Wimbledon Tennis Championships in London. Picture by Stephen Lock / i-Images

Catherine, Duchess of Cambridge, after the Gentlemen's singles final of the Championships, Wimbledon at the All England Lawn Tennis and Croquet Club in London, United Kingdom on July 14, 2019. ( The Yomiuri Shimbun via AP Images )