MELBOURNE, AUSTRALIA - JANUARY 21: Kei Nishikori of Japan hits a forehand against Pablo Correno Busta of Spain during day eight of the 2019 Australian Open at Melbourne Park on January 21, 2019 in Melbourne, Australia. (Photo by TPN/Getty Images)
MELBOURNE, AUSTRALIA - JANUARY 21: Kei Nishikori of Japan hits a forehand against Pablo Correno Busta of Spain during day eight of the 2019 Australian Open at Melbourne Park on January 21, 2019 in Melbourne, Australia. (Photo by TPN/Getty Images)