Carlos Alcaraz told to remove banned wearable device before Australian Open win, sparking rules debate

Tennis fans were left scratching their heads at Melbourne Park on Sunday after an unusual equipment call involving World number one Carlos Alcaraz briefly overshadowed his advance to the Australian Open quarter-finals.

Alcaraz beat Tommy Paul 7-6 (8-6) 6-4 7-5 to make the quarter-finals, where he will face de Minaur, who earlier thrashed Alexander Bublik 6-4 6-1 6-1.

But before Alcaraz had even struck a ball, he was approached by chair umpire Marija Cicak during the warm-up and asked to remove an item hidden beneath a wrist sweatband. The exchange was picked up by television cameras and shown on the world feed moments later.

The device in question was a Whoop, which is a screen-less wearable used by athletes to track metrics such as heart rate, sleep, physical load and recovery.

Alcaraz had been wearing it under his sweatband throughout the tournament, and Spanish media later noted he had used it in earlier rounds without incident.

While Whoop bands are approved for on-court use on the ATP and WTA tours — and the company is an official WTA partner — Grand Slams operate under separate regulations enforced by the International Tennis Federation.

Under those rules, wearables that can transmit performance data are prohibited during matches unless prior permission is granted.

That distinction has sparked debate among tennis followers, particularly since in-match coaching is now permitted.

Some argued the existing concerns about real-time data influencing tactical decisions feel outdated in a sport increasingly surrounded by analytics. Others pointed to the possibility of a competitive edge if coaches were to access biometric information at moments when direct coaching still isn’t allowed, such as during changeovers.

“You’re not allowed to play with a Whoop watch here or anything that monitors your vitals or anything else,” veteran commentator Mark Petchey observed on the broadcast after a replay of the incident aired in the opening games.

Whoop founder Will Ahmed later pushed back online, noting the device had been cleared by tennis authorities for in-match use in other competitions. “Let the athletes measure their bodies. Data is not steroids,” he posted on X.

Alcaraz was not asked about the matter in his post-match press conference, News.com reported.

On court, the 22-year-old was made to work early as Paul broke serve in the opening game and jumped to a 3-1 lead. Their tight first set was paused by a medical emergency in the crowd before Alcaraz clinched the tiebreak and rolled through the remainder of the match in two hours and 44 minutes.

The tennis star has yet to drop a set this fortnight and has been particularly effective behind his first serve, describing it as a key weapon across his first four rounds.

De Minaur, meanwhile, required just an hour and 32 minutes to sweep aside Bublik in straight sets, sending a clear signal that he intends to make life difficult for the top seed in the quarter-finals. The pair are set to meet on what is forecast to be the hottest day of the tournament, with temperatures tipped to climb as high as 44 degrees at Melbourne Park.

Should Alcaraz go on to claim his first Australian Open title, he would become the youngest man in history to complete a career Grand Slam.