MONTE-CARLO, MONACO - APRIL 18: Alexander Zverev of Germany in action during day 5 of the Rolex Monte-Carlo Masters 2019 at the Monte-Carlo Country Club on April 18, 2019 in Monte-Carlo, Monaco. (Photo by Jean Catuffe/Getty Images)
MONTE-CARLO, MONACO - APRIL 18: Alexander Zverev of Germany in action during day 5 of the Rolex Monte-Carlo Masters 2019 at the Monte-Carlo Country Club on April 18, 2019 in Monte-Carlo, Monaco. (Photo by Jean Catuffe/Getty Images)