Alexander Zverev: Faulty Glucose Sensor Left Me Unwell vs Taylor Fritz at Halle

Zverev blames glucose sensor malfunction for Halle semi-final loss to Fritz

Halle Open: Taylor Fritz beat Alexander Zverev 7-5 in the third set to extend their H2H to 7 straight wins. Zverev cited a glucose sensor malfunction but said it won’t affect his Wimbledon prep.

Fritz beats Zverev 6-7 6-4 7-5 as German cites glucose sensor problem...

Alexander Zverev said a faulty glucose sensor made him feel ill during his Halle Open semi-final loss to Taylor Fritz on Saturday. The French Open champ blamed the malfunction for his discomfort on court.

Zverev arrived with a tough head-to-head against Fritz, having lost their last six matches. That run continued as Fritz won 6-7(4), 6-4, 7-5 in a 2-hour-39-minute battle.

“I had huge problems with the sugar because the sensor I use gave me a ‌completely incorrect reading. It indicated very ⁠high values when ‌they were actually low, so I injected much more insulin than I should have,” the world number three said after the match.

“During the match, or rather during the first 45 minutes, I had to consume about ⁠350 grams of sugar. I felt absolutely terrible.”

Even with the sensor issue, Zverev said Fritz earned the win.

“Nevertheless, I fought, gave it my all, and in the end, ‌it must also be acknowledged that Taylor (Fritz) deserved the win. He played better than me today.”

Fritz takes out Zverev! 🔥

The No.5 seed makes it seven in a row against the home favourite to reach the Halle final!@Taylor_Fritz97 #TWO26 pic.twitter.com/qKBdPQBipY

— Tennis TV (@TennisTV) June 20, 2026

Zverev was diagnosed with Type 1 diabetes at age four. He relies on Medtronic tech to monitor and manage his glucose levels both during matches and away from the court.

“This is the first ‌time something like this has happened to me. I've been using these sensors since 2016 ‌or 2017, and in nine years, I had never seen such a big error,” he said.

Zverev said the glucose sensor problem won’t impact him at Wimbledon. The tournament runs from June 29 to July 12.