LONDON — Stefanos Tsitsipas stood behind the courtside sofa in the O2 Arena on Sept. 22 watching Roger Federer, Rafael Nadal, Novak Djokovic and Andy Murray practice their doubles game.
Tsitsipas applauded when Federer hit a classic backhand down-the-line passing shot — a stroke Tsitsipas has modeled his own picturesque one-handed backhand after — well out of Murray’s reach. Tsitsipas looked saucer-eyed when Federer hit another winner, this time a backhand volley off a Djokovic midcourt half volley.
Eventually, Tsitsipas, of Greece, couldn’t resist any longer, and he climbed into the umpire’s chair so he could get a better view of the four legends who would be among his teammates in the Laver Cup, starting the next day.