MELBOURNE — Wearable fitness trackers will likely be OK for players to use in future editions of the Australian Open, where leading players Carlos Alcaraz, Jannik Sinner and Aryna Sabalenka have been asked to remove their devices during matches this year.

Alcaraz and Sinner, who have split the last eight major men's singles titles between them, were approached by chair umpires during the fourth round to take off the straps they usually wear on their wrists.

Video of the interactions has drawn attention to a conflict between regular tournaments and the four majors. Sabalenka dealt with it earlier in the tournament.

Sabalenka said Tuesday she could not understand why wearing fitness trackers was banned at the Australian Open after being told to remove hers before her first-round match last week.

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 specific brand she sports.

"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."

The devices are widely used in elite sports to collect physiological data that provides insights about health and performance in training, competition, recovery and sleep.

The technology is approved for use by the International Tennis Federation and by the men's and women's tours. So far, the approval hasn't extended to the four Grand Slam tournaments, which include the Australian, French and US Opens and Wimbledon.

So, that's why the chair umpire approached top-ranked Alcaraz during his fourth-round match against Tommy Paul and asked him to take it off.

The 22-year-old Alcaraz immediately complied, taking off his sweatband and removing the strap.

"Wearables are currently not permitted at Grand Slams," Tennis Australia said in a statement.

"The Australian Open is involved in ongoing discussions on how this situation could change."

Tennis Australia said some wearables provide athletes with an indication of internal load — measures such as heart rate — "which can give them a 360-degree view of the work they're doing and how their bodies' respond".

Tournament organizers said players had access to data at the Australian Open that helped them monitor "key external load measures" such as distance covered, changes of direction, high acceleration events and speed and spin of shots.

The technology provider, WHOOP, describes it as "your 24-7 wearable coach, designed to help you improve your health, fitness, and longevity".

In a social media post, the company said the technology is "performance-enhancing — by design. That's the whole point. Taking that insight away is like asking athletes to play blind."

Sinner, the two-time Australian Open winner, said the data collected from his wrist device during matches helps with recovery and preparation for future matches.

"There is certain data that we would like to track a little bit on court. It's not for the live thing," he said. "It's more about being able to see it after the match. This is data we would like to use also in practice sessions, because, from that, you can practice knowing the heart rate, how many calories you burn, all these kinds of things."

After his fourth-round win over fellow Italian Luciano Darderi, Sinner said he also accepted the umpire's decision immediately.

"It's fine. There are other things we can use — (like) the vest. But for me, it's a bit uncomfortable — you feel like you have something on the shoulders. It's a bit different," he said. "But rules are rules. I understand. I won't use it again."

On court, Sabalenka overcame heat and one of the most exciting talents in tennis to power into the semifinals of the Australian Open on Tuesday, with Alexander Zverev serving up a storm to join her.

World No 1 Sabalenka tamed 18-year-old American Iva Jovic 6-3,6-0.

Sabalenka, the top seed from Belarus, is aiming to win a third Melbourne crown in four years and, yet to drop a set, looks in ominous form.

"These teenagers have been testing me in the last couple of rounds," said Sabalenka, 27, who is on a 10-match winning streak after victory in Brisbane earlier this month.

"It was a tough match. Don't look at the score, it wasn't easy at all. She played incredible tennis. Pushed me to step up to a better level, and I'm super happy with the win."

Zverev got the benefit of playing under a roof at Rod Laver Arena and advanced to the final four with a 6-3,6-7 (5), 6-1, 7-6 (3) win over 20-year-old Learner Tien.

The No 3-ranked Zverev, last year's runner-up in Australia, reached his 10th Grand Slam semifinal on the back of 24 aces and just a single double-fault — which he served when he had six match points in the deciding tiebreaker.