Jazz Tangcay Artisans Editor In order to deliver authenticity to every ace, volley, serve and rally, the stars of Luca Guadagnino‘s tennis drama “Challengers” each trained for up to six hours a day for three months on the court. In the film, two former friends and double partners Patrick Zweig (Josh O’Connor) and Art Donaldson (Mike Faist) face off in a challengers match years after falling out over their pursuit of Tashi Duncan (Zendaya). Brad Gilbert, tennis coach to Andy Murray and Coco Gauff, worked extensively with the actors to make sure they could convincingly become sports stars.