Why Zverev Gets Away With Using His Phone at Wimbledon

A Fans Spot Something They Should Not See

The umpire's chair is the central seat of authority at a tennis tournament. It is where the rules are enforced, the score is called, and the integrity of the match is theoretically protected. But during a recent Wimbledon encounter, eagle-eyed viewers spotted something that made them question everything they thought they knew about the sport's most sacred regulations.

Alexander Zverev, one of the most formidable players on the ATP Tour, was sitting in his chair during a changeover. But instead of simply towel drying and sipping water, he was holding something else. He was holding a mobile phone.

For a tournament steeped in tradition, where even the colour of clothing is strictly policed, allowing a player to use a smartphone during a match feels like a scandal waiting to happen. But the reality is far more nuanced.

The tournament's own guidelines explicitly prohibit the use of mobile phones during a match. It is a fundamental rule designed to protect the sport from the dangers of outside communication. Yet Zverev was not breaking any rules. He was simply operating under an exception that very few people even knew existed.

The Golden Rule That Governs Modern Tennis

To understand why Zverev's phone use raised eyebrows, you have to understand the modern panic around coaching in tennis.

The fear is simple. If a player can access a phone, they can access messages. If they can access messages, they can receive tactical advice from a coach sitting in a luxury box. That advice could be about the opponent's serve patterns, their movement limitations, or a psychological weakness the coach has spotted from a different angle.

"The integrity of tennis depends on the match being decided by the two players on the court. The moment you allow outside communication, you turn a combat sport into a team meeting."

This is not a hypothetical concern. The sport has been haunted by coaching scandals for years.

The most infamous moment came at the 2022 US Open, when Serena Williams' coach Patrick Mouratoglou admitted to making hand signals during her final against Naomi Osaka. The ensuing confrontation between Williams and umpire Carlos Ramos sparked a global debate about coaching rules that rumbles on to this day.

Wimbledon, in particular, has always been the most traditional of the Grand Slams. It operates with a stuffy, old-world strictness that feels publicly enforced. Banning phones on court is part of that brand.

The Loophole That Changes Everything

So why was Zverev allowed to keep his phone?

The answer lies in a specific medical exemption granted to the German player. Zverev suffers from Type 1 diabetes, and the phone is not for communication or tactical advice. It is for monitoring his blood glucose levels.

Zverev himself has explained how he uses the phone during matches. The device connects to a continuous glucose monitor, or CGM, that sends real-time blood sugar data to an app. Without this data, Zverev would be flying blind during a physically grueling match.

• Continuous monitoring: The CGM sensor sends blood sugar readings every few minutes.
• Alerts: The phone vibrates or alarms if blood sugar drops dangerously low or spikes too high.
• Intervention: Zverev can adjust his insulin intake or consume fast-acting carbohydrates based on that data.

If his blood sugar drops during a match, he could experience dizziness, confusion, loss of coordination, or even collapse. The phone is not a luxury. It is an anchor.

The Uncomfortable Question of Enforcement

But the Zverev exception also exposes a deeper vulnerability in how tennis governs itself.

When the rules allow a player to have a phone on court, the enforcement mechanism becomes based entirely on trust. The umpire sees the phone but does not check what the player is doing with it. The opponent sees the phone but is unlikely to challenge a medical exemption. The tournament organisers are aware of the arrangement and have signed off on it.

But what exactly is stopping a player with a legitimate medical need from also glancing at a text message from their coach?

The rules say the integrity of the match must be protected, but the practical reality is more worrying. Tennis operates on an honour system when it comes to in-match behaviour. Players are expected to call their own balls out, report themselves if they touch the net, and now, apparently, refrain from using a medical device for tactical advantage.

Precedent That Raises Eyebrows

The Zverev exemption is not without precedent, but it does set a particular kind of example.

In recent years, tennis has reluctantly moved toward legalising coaching during matches. The ATP has trialled off-court coaching, allowing coaches to communicate with players at specific times. The WTA has allowed on-court coaching for years. Wimbledon, being Wimbledon, has resisted this trend.

But the phone exemption feels like a quiet normalisation of a bigger problem.

"If a player is allowed a phone on court for medical reasons, the tournament has a responsibility to monitor how that phone is used. Trust is not a governance strategy."

In a sport where millions of dollars ride on every match point, trust is a fragile foundation. The Zverev situation highlights the need for a more robust framework.

What Could Be Done

The solution does not have to be draconian.

Tournament organisers could require players with medical exemptions to use tournament-approved devices. These devices could run only the medical apps needed, with all other functionality disabled.

Alternatively, a designated medical official could sit near the court to monitor the player's condition and communicate directly with their team, removing the need for the player to handle a personal phone at all.

The technology exists. The will to implement it seems to be the missing piece.

The Bigger Picture for Sport

The Zverev phone story is not just about one player or one rule.

It is about how sports adapt to the realities of modern athleticism. Elite athletes are no longer just physically gifted individuals. They are managing complex biological machines, often with the help of sophisticated technology.

Diabetes is not a barrier to competing at the highest level. Zverev's continued presence in the top tier of the game proves that. He has reached career-high rankings, won major titles, and competed in Grand Slam finals, all while managing a condition that requires constant vigilance.

But as more athletes come forward with similar conditions, tennis and other sports will face this question again.

A Question of Trust

For now, Zverev will continue to use his phone at Wimbledon, with the tournament's blessing.

The umpire will look the other way. The opponent will understand. The fans in the stands will probably never know the real reason the German is checking his screen between sets.

But the uneasy question will remain. In a sport where the difference between winning and losing can be a single tactical adjustment, how much trust are we willing to give to the players on the court?

Wimbledon's answer, it seems, is absolute trust. Whether that answer will satisfy the ever-watchful world of modern sport remains to be seen. For now, the phone stays on the chair, and the conversation about what it represents continues to echo through the sport.

The All England Club prides itself on being the guardian of tennis tradition. But in accommodating Zverev's medical needs, it has quietly opened a door that many thought was locked. How it manages that door in the coming years will say a lot about the future of the sport's governance.

Updated: 2026-07-10 — Added Zverev's own explanation of how he uses his phone to monitor blood glucose levels due to his Type 1 diabetes.