Tennis’s premier Grand Slam, the Australian Open, has become the centre of an unexpected technology dispute after leading players Carlos Alcaraz and Aryna Sabalenka were instructed to remove wearable fitness devices before their matches.

Umpires at Melbourne Park asked both the men’s and women’s world No. 1s to take off low-profile WHOOP bands—wrist-worn trackers that monitor heart rate, recovery, strain and other physiological metrics—because the tournament’s current rules prohibit such wearables during play.

The requests drew widespread attention given that the International Tennis Federation lists the devices as approved for in-match use under its regulations, provided they do not communicate real-time information to players or coaches.

The incident unfolded prior to Alcaraz’s fourth-round match, when the device was spotted under his sweatband and he complied with the umpire’s order to remove it.

Sabalenka had been similarly asked to remove her WHOOP band earlier in the tournament before one of her matches, prompting visible frustration.

A further instance involving another top player reinforced the impression that the prohibition is being strictly enforced at this year’s Australian Open, even for devices widely accepted on the ATP and WTA tours outside of the Grand Slams.

WHOOP’s founder and representatives publicly defended the technology, arguing that granting players access to their own health and performance data poses no competitive or safety risk and should be permitted.

They emphasised that the devices do not provide strategic signals or communication with coaches during matches and are intended simply to support athletes’ understanding of their physical condition.

Many observers have noted the inconsistency between the tournament’s ban and broader sport-wide approvals, prompting discussion about whether rule harmonisation is necessary.

Tennis officials have not yet issued a comprehensive statement explaining the rationale behind the enforcement, but the controversy has crystallised around the autonomy of Grand Slam tournaments to interpret wearable-technology policies independently of the global governing body.

Players have largely complied with the rulings without protest, focusing instead on their performances as the tournament progresses.

The incidents, however, have opened up a broader conversation about how wearable technology and data should be treated in elite competition and whether existing regulations need updating to reflect modern athletic practice.