ATP Masters Series: Monte Carlo Rolex Masters - Day Seven [Getty Images]

MONTE-CARLO, MONACO - APRIL 21: Kei Nishikori of Japan reacts after his men's Semi-Final match against Alexander Zverev Jr. of Germany during day seven of ATP Masters Series: Monte Carlo Rolex Masters at Monte-Carlo Sporting Club on April 21, 2018 in Monte-Carlo, Monaco. (Photo by Julian Finney/Getty Images)

Getty Images Sport Julian Finney