World number one Jannik Sinner has withdrawn from this week's Cincinnati Open because of a knee injury, but still expects to be fit for the US Open later this month.

The 24-year-old Italian won his fifth Grand Slam singles title by beating Alexander Zverev in the Wimbledon final last month, but has not played since.

"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.

"My right knee has been bothering me, and even though we have been working hard with my medical team, I have to accept I'm not ready to compete yet.

"I'm very disappointed not to be able to play in Cincinnati. I can't wait to be back next year and I'm now focusing on getting ready for the US Open."

The Cincinnati Open main draw begins on 13 August, with the final on 23 August. Zverev and 24-time Grand Slam champion Novak Djokovic are among those in action.

Spain's Carlos Alcaraz won the 2025 event and was leading 5-0 in the final against Sinner, before the Italian had to retire because of illness.

But world number two Alcaraz, 23, will not be there to defend his title as he has not played since the Barcelona Open in April because of a wrist injury.

The US Open, the last Grand Slam of the year, takes place in New York from 30 August to 13 September.