While Nadal, he says, is more likely to reply to messages rather than initiate them, Federer is the chief instigator. “Roger is the funniest among everyone, he likes to send jokes and funny videos.

“I hope people don’t call him Baby Fed so often anymore,” Federer told reporters. “At first it’s funny, but it gets annoying.” Coach and analyst Darren Cahill then told the New York ...