The Masters 1000 in Cincinnati just wrapped. And it was not the ending anyone expected. What promised to be another fiery showdown between Jannik Sinner and Carlos Alcaraz lasted only 23 minutes before the Italian pulled out. He came in hot after two brilliant weeks, reaching back-to-back finals without dropping a set. But the defending champion couldn’t finish this one. Now, his road to the next Grand Slam looks a little bumpier.

On Monday against Alcaraz, already trailing 0-5 in the opener, Sinner called for a medical timeout. Illness struck under the sweltering Ohio sun with temperatures over 30 degrees Celsius. After a chat with the on-court medics, he retired, handing Alcaraz his first Cincinnati title. But Sinner stayed positive, telling ATP, “Now I have already some points where I need to improve if I want to go far in US Open. And it was a good test this week, trying to understand where my level is. My level is, is in a good spot, for sure, but in the other way, there’s still room to improve. So, but yeah, it was, was a great week.” Next, he turns to the mixed doubles spotlight in New York, which boasts the top prize of $1 million.

Tomorrow, he’ll debut with a brand-new partner, doubles No.2 Katerina Siniakova. Grand Slams always light a fire in Jannik Sinner, as he added, “I love Grand Slams a lot. This is the main, main tournaments for, for my season and, you know, for my career. So US Open is going to be tough tournament, but in the same time, I’m looking forward to it. If I’m ready, physically and mentally, I’m, I will be ready to push.” That’s the goal.

He’s usually sharp in Cincinnati, but it was a different story this time around. Early on, his serve faltered, forcing him into a late-night practice session with coaches Simone Vagnozzi and Darren Cahill right after his match against Gabriel Diallo. The heat didn’t help either. Jannik Sinner struggled again in the semis versus rising star Terence Atmane.

The Italian poured water over his head during changeovers, fighting through exhaustion in the first set. Still, he clawed back, beating Atmane 7-6(4), 6-2 to reach the final. The brutal conditions affected almost everyone—Daniil Medvedev, Andrey Rublev, Carlos Alcaraz, and Ben Shelton all voiced concerns. The Ohio heat gave no favors.

Now Jannik Sinner heads to the US Open as defending champion. His withdrawal here raises questions, especially since he’s set to take the court tomorrow with Siniakova. His former partner, Emma Navarro, pulled out of playing the Monterrey WTA 500. The switch could work in Sinner’s favor.

After all, Siniakova brings pedigree. The Czech is a ten-time Major winner, a former world No.1, and an Olympic Games champion. At 29, she’s stacked an impressive mixed doubles resume that Sinner lacks. She lifted Olympic gold last year and added her first Wimbledon mixed title just weeks ago. Pairing her with the ATP World No.1 could deliver fireworks.

For now, Sinner wants rest before the Slam grind begins. “Now, a couple of days of recovery, and then, you know, we get again back to work, and hopefully we’ll be ready. So for sure, the main goal here in the US.” The Italian has shown resilience all year. Cincinnati left him gutted for fans, but with his track record of bouncing back, he may well unleash his best when it matters most.

Jannik Sinner speaks to fans following a walkover

At the trophy ceremony, Sinner couldn’t help feeling bad for his fans. “Usually I start with the opponen,t but today I have to start with you guys. I’m super, super sorry to disappoint you. From yesterday, I didn’t feel great. I thought I would improve during the night,” he admitted. “It came up worse. I tried to come out and make it at least a small match, but I couldn’t handle more.”

This loss snapped Jannik Sinner’s 26-match winning streak on hard courts. Now his focus turns to a quick recovery before defending his US Open crown. The season hasn’t been smooth—just six tournaments played, with titles at the Australian Open and Wimbledon, but defeats in the finals at the Italian Open and Roland Garros. Paris hurt the most, where he led Alcaraz by two sets, held three championship points, and still fell in a super tiebreak of the decider.

Redemption came later at SW19, when he beat the same opponent. Across it all, he also served a three-month WADA ban, from February 9 to May 4, after last March’s positive test. Yet, he’s reached every Slam final this year, becoming the youngest Italian to make four straight since the 2024 US Open.

Whether he joins Katerina Siniakova on Tuesday in mixed doubles is still uncertain. His health needs to recover quickly after the quick trip from Ohio to New York. Will Jannik Sinner be ready in time? For now, it’s one of the big questions hanging over the US Open. What do you think?