World number one Jannik Sinner has pulled out of the Cincinnati Open with a right knee ​injury, tournament organisers said on Sunday, handing the ‌Italian a blow in his preparations for this month's U.S. Open. Sinner won the Cincinnati title in ​2024 and finished runner-up to seven-times Grand Slam champion ​Carlos Alcaraz there last year. "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. Sinner's withdrawal ​further ⁠depletes the field in Cincinnati, with U.S. Open champion Alcaraz also sidelined by a wrist injury. The Cincinnati Open main ⁠draw ​begins on August 13, while ​the U.S. Open main draw gets under way on August 30.