World number one Jannik Sinner said Friday he is “not 100% yet” but expects to be at full strength for the launch of his US Open title defense when the final Grand Slam of 2025 gets underway.

The Italian retired because of illness while trailing Carlos Alcaraz 5-0 in the first set of the Cincinnati Open final on Monday and pulled out of the Open’s new-look mixed doubles competition on Tuesday and Wednesday.

READ: Jannik Sinner vows to play at US Open after Cincy retirement

Speaking to reporters at the Billie Jean King National Tennis Center at Flushing Meadows on Friday, Sinner said he was highly motivated and on the mend two days before singles action was slated to start.

“So physically, I feel good,” said Sinner, who is expected to play his first match against Czech Vit Kopriva on Monday.

“You know, I have recovered mostly, not 100% yet, but we are aiming to be there in a couple of days. So should be all fine for the tournament.

“It was a virus, also some other players had,” Sinner added. “Just sleeping and recovering. Nothing crazy.”

READ: Jannik Sinner withdraws from US Open mixed doubles draw

Sinner’s growing rivalry with Alcaraz is in the spotlight at the Open. Their five meetings in Grand Slams include two finals this year, with Alcaraz triumphing at Roland Garros and Sinner turning the tables at Wimbledon.

Sinner said the differences in their games and personalities make the rivalry more compelling, but one main trait they share is a laser-like focus on the game.

“We make choices for tennis,” Sinner said. “It’s now our first priority at the moment, which it has to be because it’s very small, small details make the difference.”

Jannik Sinner of Italy addresses the crowd after his match against Carlos Alcaraz of Spain during the men’s final of the Cincinnati Open at Lindner Family Tennis Center on August 18, 2025 in Mason, Ohio. Matthew Stockman/Getty Images/AFP

Sinner’s US Open title last year came amid a doping scandal in which he first escaped a ban before eventually agreeing to a three-month suspension — even though doping authorities accepted that his exposure to the anabolic steroid clostebol was accidental.

“Last year was a much more stressful situation,” Sinner said. “It was difficult to handle everything. You know, I’m still young, so it was not easy.”

Since serving his ban following his victory in the Australian Open in January, Sinner has rehired fitness coach Umberto Ferrara, who had been sacked along with physiotherapist Giacomo Naldi after the revelation of Sinner’s positive tests.

Now the Italian is ready to move on as he tries to become the first man to repeat as US Open champion since Roger Federer won five in a row from 2004-2008.

“I feel like it’s over,” he said. “We are focusing on hard work again and trying to get better as an athlete.

“I’m very happy to be back here,” Sinner said. “It’s obviously the last Grand Slam we have for this season so the motivations are very high.”