It was close to 1 p.m. on Thursday, and Alexander Zverev, better known as Sascha, was running late. He sat in the back seat of an S.U.V. making its way from the Billie Jean King National Tennis Center in Queens to Manhattan’s Upper West Side for a photo shoot. He had no time to eat, so he brought four trays of sushi.
Patricio Apey, Zverev’s agent, took a long breath and rattled off the commitments on Zverev’s schedule for the days before the United States Open — five-hour photo shoot with Adidas, charity event, player party and a sponsor event where Zverev would play badminton in a courtyard.