MELBOURNE, AUSTRALIA – JANUARY 28: Roger Federer of Switzerland plays a backhand in his quarter final match against Tennys Sandgren of the United States on day nine of the 2020 Australian Open at Melbourne Park on January 28, 2020 in Melbourne, Australia. (Photo by TPN/Getty Images)
MONTE-CARLO, MONACO – APRIL 20: Fabio Fognini of Italy plays a backhand volley against Rafael Nadal of Spain in their semifinal match during day seven of the Rolex Monte-Carlo Masters at Monte-Carlo Country Club on April 20, 2019 in Monte-Carlo, Monaco. (Photo by Clive Brunskill/Getty Images)
Photo by Martin Cole/ProSports/REX/Shutterstock (9980575w) Kei Nishikori of Japan celebrates during the Nitto ATP World Tour Finals at the O2 Arena, London. Picture by Martin Cole 15/11/2018., Nitto ATP Tour Finals, Tennis – 15 Nov 2018