Jannik Sinner stunned tennis fans when he retired just 23 minutes into the men’s singles final at the Cincinnati Open against Carlos Alcaraz on Monday, Aug. 18. The Italian star, trailing 0-5 in the opening set, appeared visibly unwell, prompting concern about his fitness heading into the 2025 US Open.
Sinner’s coach, Darren Cahill, later confirmed that the exit was due to a virus, offering reassurance that the world No. 1 is on the mend and expected back on court soon for his title defense.
What Updates Did Coach Darren Cahill Provide on Jannik Sinner’s Health?
The Cincinnati Open has historically been a key warmup for the US Open, with players testing their form and endurance under the summer heat. For Sinner, who was riding a 12-match winning streak, the abrupt retirement was a jolt to fans and spectators.
So very sad to see 💔@carlosalcaraz comforts a disappointed Jannik Sinner after the World No. 1 is forced to retire due to illness.@CincyTennis | #CincyTennis pic.twitter.com/RzCZJGVPUT
— ATP Tour (@atptour) August 18, 2025
The final coincided with peak afternoon temperatures in Cincinnati, a factor that may have worsened his physical strain. Sinner embraced Alcaraz before leaving the court, hiding his face in a towel, while Alcaraz showed sportsmanship by writing “Sorry Jannik” on a TV camera lens and sending well wishes on social media.
During the trophy ceremony, Sinner addressed the crowd, expressing his deep regret: “I’m super, super sorry to disappoint you guys. Since yesterday, I didn’t feel great. I thought that I would improve during the night, but it came up worse. I tried to come out, trying to make it even in a small match, but I couldn’t handle more.”
“From yesterday, I didn’t feel great.” 😓
Jannik Sinner speaks after retiring in the Cincinnati final.
Wishing the World No. 1 a speedy recovery 💕#CincyTennis pic.twitter.com/IjRr1omqGL
— Tennis Channel (@TennisChannel) August 18, 2025
The illness raised questions about how Sinner would handle the Grand Slam in New York just days later. Sinner issued only a brief statement confirming that he would compete in the U.S. Open singles tournament beginning Sunday.
Cahill provided an update during an appearance on ESPN on Wednesday. “Jannik suffered from a virus that forced him to retire against Alcaraz on Monday. He’s feeling a bit better now, will rest today, and is expected back on court Thursday. We are confident he’s going to be fine,” Cahill said ahead of the US Open draw release on Thursday.
The illness also disrupted plans for the revamped mixed doubles event at the U.S. Open. Sinner had been scheduled to team up with doubles specialist Katerina Siniakova as a wildcard pairing against Alexander Zverev and Belinda Bencic. He withdrew hours before the match, and the tournament listed Christian Harrison and Danielle Collins as replacements.
