Jakub Mensik has enjoyed a breakout year in 2025, but could be in danger of missing the final Grand Slam of the season.

The Czech star became the latest victim of the harsh conditions in Cincinnati as Mensik retired from his third-round match with Luca Nardi, trailing 2-6, 1-2.

In doing so, Mensik became the seventh player to have retired mid-match at this year’s Cincinnati Open.

A general view of Center Court at the 2025 Cincinnati OpenPhoto by Daniel Kopatsch/Getty Images

The 19-year-old now faces a race against time to compete at the US Open, an event which begins in just ten days.

Updating his fans with the final Grand Slam of the year right around the corner, Mensik has issued a health update on social media.

Jakub Mensik says he was ‘running on empty’ after illness in Cincinnati but aims to be fit for US Open

Sharing a health update on X, Mensik explained how he felt during his third-round defeat to Nardi.

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“The two days leading up to yesterday’s match were super rough, something hit my stomach hard, and it was far from a pleasant experience,” he said.

“I tried my best to be able to compete and to fight, but unfortunately, by match time, my energy was gone… running on empty.”

Mensik did, however, suggest he will be back fit in time for the US Open.

Jakub Mensik reacts during his third-round match at the 2025 Canadian OpenPhoto by Julian Avram/Icon Sportswire via Getty Images

“I’m focusing on recharging and getting ready for US Open,” he said.

“Huge thanks for all your support and well wishes.

“I’m aiming to have my full energy back soon so I can give it my all in New York.

“See you all soon!”

Mensik will desperately hope to regain full fitness before the US Open, statistically his most successful Grand Slam tournament.

Grand Slam 2023 2024 2025 Win/Loss record Win % Australian Open – 2R 3R 3-2 60% French Open – – 2R 1-1 50% Wimbledon – 1R 3R 2-2 50% US Open 3R 3R – 4-2 67%

Jakub Mensik’s record at Grand Slams

Appearing at the US Open twice previously, Mensik reached the third round in 2023 and 2024, winning four matches and losing two.

Mensik secured one of the biggest wins of his professional career 12 months ago, knocking out former Grand Slam semifinalist Felix Auger-Aliassime in round one.

He’ll be looking to pull off another upset in New York this time around, should he be fit to compete.

You wouldn’t want to bet against him doing just that as Mensik continues to pick up big wins on the ATP Tour, despite his age.

Jakub Mensik is the best teenager on the ATP Tour

Aged 19, Mensik is a top 20 player in the men’s game, and is the only teenager currently ranked inside the world’s top 50.

What’s more impressive is the way Mensik has built up his ranking, as the Czech star has defeated some of the world’s best players on his way to the top.

Rather than picking up smaller tour-level trophies, Mensik won his maiden ATP title at the Miami Open Masters 1000 event, picking up three top-ten wins en route to the title.

Rank ATP Rank Name Nationality Age Titles Top-ten wins 1 17 Jakub Mensik Czech 19 1 (2025 Miami Open) 8 2 52 Joao Fonseca Brazilian 18 1 (2025 Argentina Open) 1 3 55 Learner Tien American 19 – 4 4 142 Martin Landaluce Spanish 19 – – 5 163 Nicolai Budkov Kjaer Norwegian 18 – – 6 200 Rei Sakamoto Japanese 19 – – 7 227 Justin Engel German 17 – – 8 230 Federico Cina Italian 18 – – 9 338 Diego Dedura German 17 – – 10 342 Joel Schwarzler Austrian 19 – –

Top-ten ranked teenagers on the ATP Tour

Set to turn 20 during the US Open, Mensik can be proud of his ATP Tour efforts as a teenager, achieving results very few could even dream of.

Currently sitting less than 1,000 points outside of the top ten, Mensik will be in with a shout of finishing the year ranked among the world’s best should he pick up some more strong results over the next few months.

The sky is the limit as far as Mensik is concerned, but he won’t want to get too far ahead of himself, as he first focuses on regaining fitness ahead of the US Open.

This year’s US Open tournament is scheduled to begin on Sunday, August 24.