Jannik Sinner’s withdrawal from the Cincinnati Open has done more than reshape one tournament draw.

It has put a question mark, however faint, over the world number one’s US Open fitness as he reportedly prepares for the tournament in New York later this month, just as the tour heads into its final and most demanding stretch of the season.

The Italian, who has not hit a competitive ball since lifting the Wimbledon trophy in July, confirmed on Sunday that a troublesome right knee had forced his hand.

“After consulting with my doctors and my team, I have to announce that I need to withdraw from the Masters 1000 tournament in Cincinnati,” Sinner said in a statement, adding that despite working hard with his medical team he had to accept he was “not ready to compete yet”.

The timing matters, since Cincinnati has long served as the dress rehearsal for the US Open, the last big hard-court test before players fly to New York.

Skipping it means Sinner heads into the tournament carrying real doubts about his US Open fitness, with no match play at all since Wimbledon to fall back on.

Sinner’s own explanation was blunt rather than dramatic: the knee has been bothering him for some time, and this is a precaution rather than a crisis, at least in his telling. 

“I’m very disappointed not to be able to play in Cincinnati,” he said. “I can’t wait to be back next year and I’m now focusing on getting ready for the US Open.”

That framing, of a player protecting himself for the bigger prize rather than nursing a serious setback, is the version his camp wants out there. 

Whether it holds up over the coming fortnight will say a lot about how his season finishes, and how his US Open fitness holds together under real match pressure.

US Open Fitness Doubts Follow Cincinnati Pullout

Sinner’s route to that second Wimbledon title was already gruelling. He stayed off tour between the French Open and Wimbledon, where he defeated Carlos Alcaraz in the final to claim his first title at the All England Club.

How that draining run connects to his current knee trouble is not fully known, and beyond his own statement, the finer points of his medical situation have not been independently verified.

What is clear is the arithmetic, since a player who has not competed in roughly a month now has to find tournament sharpness in a matter of weeks with no warm-up event to lean on. How his knee responds to full training load will matter far more than anything said in a press release.

Cincinnati Open Draw Loses Its Biggest US Open Fitness Test Cases

Sinner’s absence leaves a genuine hole at the top of a Cincinnati field that ran from 7 to 18 August, though it is far from the only one

Carlos Alcaraz, last year’s champion and ranked among the world’s top three, also sat out due to an ongoing wrist injury that has kept him sidelined for months.

That means the two biggest names in the men’s game were both missing from the tournament that produced last year’s most dramatic final, when Sinner had to retire while trailing Alcaraz due to illness. 

The draw was not without star power regardless, since Alexander Zverev and 24-time Grand Slam champion Novak Djokovic remained confirmed to play, giving organisers at least two box-office names to build around even with its top two seeds gone.

None of that changes the bigger picture hanging over the sport’s American swing, with the US Open beginning in New York on 24 August and running through to 7 September.

Sinner’s tournament there is set to be the first real test of his fitness after this withdrawal, and how his US Open fitness holds up will shape the rest of his season.