World No. 1 Jannik Sinner has withdrawn from the Cincinnati Open after revealing he is dealing with a right knee injury, raising concerns over his fitness with the US Open just weeks away.

Sinner has not competed since claiming the Wimbledon title in July and will now miss a second consecutive Masters 1000 event after also sitting out the ongoing Canadian Open.

The Italian confirmed his withdrawal after consulting with his medical team and coaches.

“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 that I’m not ready to compete yet.”

Sinner expressed his disappointment at missing the tournament and thanked the organisers for their efforts.

“I’m very disappointed not to be able to play in Cincinnati and wish Bob and his whole team a great and successful event. I can’t wait to be back next year and I’m now focusing on getting ready for the US Open.”

Sinner began the year in impressive fashion, winning five consecutive Masters 1000 titles and becoming only the second player after Novak Djokovic to complete the full collection of ATP 1000 crowns. The Italian also lifted the Cincinnati Open trophy in 2024.

His focus will now turn to making a full recovery in time for the US Open, the final Grand Slam of the season. Sinner reached the final in New York last year, where he was beaten by Carlos Alcaraz. The two rivals have dominated men’s tennis in recent years, winning 10 of the last 11 Grand Slam titles between them.

The Cincinnati Open gets underway on August 13, but the tournament will now be missing both Sinner and Alcaraz. Djokovic, meanwhile, is set to return to the event for the first time since 2023, with the 24-time Grand Slam champion adding significant star power to the field.