MONTE-CARLO, MONACO - APRIL 21: General view inside the stadium as Alexander Zverev Jr. of Germany plays against Kei Nishikori of Japan in their men's Semi-Final match 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)
MONTE-CARLO, MONACO - APRIL 19: Novak Djokovic of Serbia plays a shot against Roger Federer of Switzerland during their semi final match on day seven of the ATP Monte Carlo Masters, at the Monte-Carlo Country Club on April 19, 2014 in Monte-Carlo, Monaco. (Photo by Mitchell Gunn/Getty Images)
