Jannik Sinner was caught wearing a banned wrist device moments before the start of his Australian Open fourth-round match against Luciano Darderi.
The defending Australian Open champion was ordered to remove what appeared to be a Whoop fitness tracker after he was busted by umpire Greg Allensworth.
Sinner was wearing the technology under his left wristband, but Allensworth spotted it as the player came to the net for the pre-match coin toss, and the Italian removed it without complaint.
It comes as Carlos Alcaraz was also ordered to remove a similar device on Sunday, while Aryna Sabalenka was also caught out earlier in the tournament. Alcaraz also attempted to hide the device under his wristband.
Sinner, 24, struggled in the extreme heat and admitted he got “lucky” with the enforcement of the tournament’s heat rule as he battled cramp against Eliot Spizzirri in his previous match on Saturday.
The Whoop wristband can measure fitness and biometric data, including heart rate and body stress, which can also inform recovery.
After Alcaraz was caught on Sunday, the Whoop founder and CEO Will Ahmed posted on X: “Ridiculous. Whoop is approved by the International Tennis Federation for in-match wear and poses no safety risk. Let the athletes measure their bodies. Data is not steroids!”
Tennis Australia, the organisers of the Australian Open, have confirmed that wearable technology is not permitted at grand slam tournaments – but the International Tennis Federation (ITF) has the Whoop wrist device on its list of approved Player Analysis Technology. The devices are also allowed on the ATP and WTA tours.
A Whoop spokesperson said: “Whoop believes athletes have a fundamental right to understand their own performance and health – including during competition at events like the Australian Open.
“Whoop is approved by the International Tennis Federation for in-match wear and poses no safety, fairness, or competitive risk. Blocking access to personal health data does not protect sport. Whoop will continue to stand with athletes and our members to defend their right to their data.”
