NEW YORK, NY - AUGUST 25: Novak Djokovic plays tennis during the 2018 Arthur Ashe Kids' Day at USTA Billie Jean King National Tennis Center on August 25, 2018 in New York City. (Photo by Noam Galai/Getty Images)
NEW YORK, NY - AUGUST 25: Novak Djokovic plays tennis during the 2018 Arthur Ashe Kids' Day at USTA Billie Jean King National Tennis Center on August 25, 2018 in New York City. (Photo by Noam Galai/Getty Images)