TENNIS: Zverev plays 'two games at once' as diabetes clock ticks under Australian Open run

MELBOURNE — On tennis’s biggest stages, Alexander Zverev moves according to the arena’s timing — the serve clock, the changeover, the rhythm of the match. But beneath the noise, a quieter countdown runs through his body: his blood sugar.

“There are definitely two games happening at the same time,” Zverev told Reuters recently, describing life with type 1 diabetes. “There’s the match everyone sees, and then there’s the one only I feel. If I don’t manage my diabetes properly, I can’t compete at the level I expect.”

The German third seed will face Learner Tien on Tuesday for a spot in the semifinals, a year after losing the Melbourne final to Jannik Sinner.

At 28 years old and ranked world No. 3, Zverev has already achieved major success, including an Olympic gold medal, two ATP Finals titles, and three Grand Slam final appearances. Still, he remains in search of the one trophy that has eluded him.

Diagnosed with diabetes at age four, Zverev says the condition isn’t a barrier — it’s a second match running alongside the first. It punishes haste and rewards routine.

“Most of the time, it’s preparation that keeps them aligned,” he said. “When something unexpected happens, I’ve learned to stay calm and trust the systems I have in place.”

That second match is mostly hidden, he said, managed quietly between points and changeovers.

“Probably something as simple as when to take a sip from my bottle or choose to have an energy gel,” he explained. “From the outside it just looks like a routine changeover, but I’m already planning my next change of ends.”

Off the court, Zverev uses a Medtronic insulin pump — a wearable device that delivers measured insulin to help regulate glucose. However, he cannot wear it during competition.

His career has also been marked by controversy. He settled a case last year involving allegations that he pushed and strangled a former girlfriend, allegations he denied. The ATP later dropped another investigation due to insufficient evidence.

On the court, Zverev focuses on the small, often unnoticed decisions that help him manage his diabetes while keeping his attention on the match.

“These are tiny decisions, but they matter,” he said. “You don’t need to stop the match or make a big moment out of it. It’s about staying one step ahead so the tennis can stay in focus.” -Reporting by Lidia Kelly in Melbourne; Editing by Peter Rutherford/Reuters