The world No. 1 highlighted that she and fellow players had been granted permission by the International Tennis Federation (ITF) in December to use the technology, only to discover at the Australian Open that Grand Slam tournaments have a different policy. “The reason why I was wearing that on court is because we received the email that we got approval from the ITF to wear this device,” Sabalenka said after her quarter-final win over Iva Jovic. “I didn’t know that Grand Slams didn’t come to a conclusion.”

Alcaraz was halted mid-match when an official spotted the tracker beneath his wristband, while Sinner was required to remove his device ahead of his fourth-round clash against Luciano Darderi.

Wearable fitness trackers are allowed on both the ATP and WTA Tours. The WTA has been in partnership with Whoop since 2021, and the ATP gave the green light to in-match use of the technology in 2024.

The ITF also authorised the devices towards the end of last year. However, the four Grand Slams, which operate independently, have yet to sanction their use during competition.

Tennis Australia confirmed that wearable devices are presently prohibited at Grand Slam tournaments, including the Australian Open, but stated that deliberations are continuing.

“Wearables are currently not permitted at Grand Slams,” a spokesperson said. “The Australian Open is involved in ongoing discussions on how this situation could change.”

Sabalenka argued the prohibition makes little sense considering how extensively the technology is utilised throughout the remainder of the tour. She stressed that the tracker is not designed to deliver any competitive edge during matches, but instead to assist with monitoring health and recovery.

“The whole year we are wearing – on WTA tournaments, all the tournaments I play – we wear Whoop. It’s just for tracking my health,” she said. “I don’t understand why Grand Slams are not allowed us to wear it.”