Sabalenka 'does not understand' Australian Open fitness tracker ban
Data analytics is a key part of elite sport performance and tennis players routinely have the screenless tracking bands on their wrists.
They are allowed on the ATP and WTA tours, but not at Grand Slams.
"The reason why I was wearing that on court, because we received the email that we got approval from the ITF to wear this device," she said, referring to the International Tennis Federation.
"I didn't know that Grand Slams didn't come to (the same) conclusion.
"I don't understand why, because the whole year we are wearing, on WTA tournaments, all the tournaments I play we wear WHOOP," added Sabalenka, referring to the brand name.
"It's just for tracking my health. I don't understand why Grand Slams are not allowing us to wear it and I really hope that they will reconsider the decision and let their players track their health."
Sabalenka was asked to remove one before her first-round match last week.
Carlos Alcaraz and Jannik Sinner also fell foul of the regulations in Melbourne.
"There is certain data what we would like to track a little bit on court," said Sinner after his fourth-round victory on Monday.
"It's not for the live thing. It's more about what you can see after the match."
The trackers can help monitor physical exertion, stress levels and heart rate.
The Australian Open said it was "involved in ongoing discussions" about players wearing the devices in future, but gave no explanation to why they could not do so now.