No Sweat. Frances Tiafoe Would Like a Fresh Shirt Now.

During a changeover 26 minutes into his second-round match against Sebastian Ofner, Frances Tiafoe reached into his bag, pulled out a fresh top and changed his shirt. Twenty-four minutes later, up by 4-1 in the second set, he swapped that shirt for a clean one again.

Between the second and third set, Ofner took a medical timeout. Tiafoe had been wearing his shirt for only about six minutes, but he was ready for another.

Before the match ended, Tiafoe changed his teal sleeveless shirt once more. By the end of his straight-sets victory over Ofner, there was a pile of sweaty shirts by Tiafoe’s bench. He picked them all up and stuffed them into his bag before leaving the court. (Those shirts are later given to the U.S. Open staff members who take care of the laundry.)

Through the fourth round, Tiafoe had changed his top 20 times, an average of five times per match.

He will usually return to his bench, hydrate and towel off his face and body before slipping into a fresh shirt. He has no specific method for determining when he needs to change. Sometimes he’ll grab a fresh shirt out of his bag at the end of a set. Other times, he will change multiple times in a single set.

It is not uncommon for a player who has been sweating in a competition to change into a clean shirt a few times each match. But Tiafoe has taken freshening up to an elite, seemingly compulsive level.

If he feels uncomfortable, he wants a fresh top.

“You want to be as light as you can on the court,” Tiafoe said after his second-round victory, adding that if he feels even a small amount of moisture on his shirt, he’ll change it. “I’m very adamant about that.”

Many athletes have quirks. Superstitious baseball players hop over foul lines to avoid bad luck. Rafael Nadal, the 22-time Grand Slam champion, is steadfast about having two water bottles by his bench positioned diagonally from each other with the logos facing the court. For Tiafoe, it is a near obsession with changing shirts — perhaps more than any other player on the men’s tour.

At tournaments, many players wear one outfit and stick with it; others swap out an outfit only if it is uncomfortable or seems unlucky. At last year’s U.S. Open, Bianca Andreescu, the 2019 U.S. Open champion, asked an umpire for permission to change her outfit in the middle of a match.

Players can change tops from their benches during matches. Men are allowed two opportunities to leave the court for a complete outfit change in a best-of-five match, and women are allowed one change of attire in a best-of-three match.

“Shirts, socks and shoes should be changed on court,” the International Tennis Federation rule book says.

At this year’s U.S. Open, Tiafoe has sported a teal, sleeveless top patterned with shades of baby blue, coral, peach and maroon. He has completed his ensemble with teal shorts and a pair of bright red shoes with his nickname, Big Foe, across the heels.

Tiafoe said he packed as many as 20 tops in his bag to be sure he had enough for his matches. He also takes two extra pairs of shoes, in case a pair becomes too sweaty.

“I don’t want to feel like I’m playing with really sweaty clothes just because I’m not prepared,” Tiafoe said. “I know how much I can sweat.”

And Tiafoe sweats a lot. In a couple of his matches at this tournament, even after he has changed shirts, Tiafoe has needed help from a ball crew member to peel his shirt off his back because the top had stuck to his shoulders.

The weather at the U.S. Open has appeared to play a role in how many times Tiafoe has changed clothes.

In his first-round match, the humidity levels made playing conditions feel muggy inside Arthur Ashe Stadium. In that match, against Learner Tien, Tiafoe changed his shirt six times.

But even after a cold front swept through New York in time for Tiafoe’s second- and third-round matches, he perspired enough to change four times on Wednesday against Ofner and four times on Friday against Adrian Mannarino.

By his fourth-round match against Rinky Hijikata on Sunday, temperatures had reached 88 degrees. This week, the forecast is for humid days with temperatures into the 90s through Thursday, above normal for this time of year in New York, before settling into the 80s for the semifinals and final.

When Tiafoe plays Ben Shelton in the quarterfinals on Tuesday that will probably mean more sweat and more shirt changes.

But who’s counting?