For the tournament, it’s a chance to gain an extra bit of attention and position itself as an aspirational event.

Sometimes the famous folks ask for tickets. Sometimes they’re invited by the USTA, which uses an outside firm to help contact publicists, managers and agents and will provide rides to and from the tournament.

“If we know somebody’s in town — maybe they’re shooting a movie, maybe they’re shooting a television series, maybe they’re here for the (MTV Video Music Awards) — and we have a relationship with the person who handles them,” Widmaier said, “we might say, ‘Hey, by the way, if so-and-so is interested, we’d love to host them if their schedule permits.’”

And sometimes a player issues the invitation.

Tiafoe arranged for rapper Pusha T to be at one of his matches this year.

“My agent took care of him. I got him courtside. That was pretty cool,” said Tiafoe, a 25-year-old from Maryland who lost in the quarterfinals to Ben Shelton on Tuesday, when actress Emma Watson and Vogue editor-in-chief Anna Wintour were on hand. “As soon as I saw him there … I wanted to dap him up and say thanks for coming out. It was good. Obviously the U.S. Open put that on Instagram right away. Pretty smart.”

Make no mistake: The players are aware of who’s there.

“I notice when they’re watching,” said defending men’s champion Carlos Alcaraz, who won in front of singer J Balvin and actor Ben Stiller on Monday. “Sometimes, (I think), ‘Oh, my God, he’s there or she’s there.’ It’s crazy.”

Yes, the celebrities from the worlds of entertainment, politics and other sports are a hit with the players — especially if they can connect after a match.

“I was definitely starstruck with Justin Bieber. ‘Never Say Never’ was … one of my favorite songs when I was a kid. Then ‘Baby, Oh, Baby.’ I could go through all his songs. Then Hailey, too, coming,” said Gauff, a 19-year-old from Florida. “I guess it was a little date night for them, which was really cool.”

She had met first lady Michelle Obama previously, but not former President Barack Obama, and was thrilled to get to chat with both after they watched her win on the tournament’s opening night.

“I wasn’t sure they were here or not. I saw the Secret Service. I didn’t know if it was Mr. Biden and Mrs. Biden. I knew it was somebody. Then I heard that maybe Mr. Clinton was coming. I didn’t know who exactly it was. So I didn’t know until after the match,” Gauff said. “I’m going to never forget that moment for the rest of my life.”