Jannik Sinner withdraws from Cincinnati Open with knee injuryWorld No. 1 Jannik Sinner has withdrawn from the Cincinnati Open with a right knee injury, further disrupting his US Open preparations. The Italian, who also missed the Canadian Open, now has limited time to regain fitness before the final Grand Slam. 1 Jannik Sinner has withdrawn from the Cincinnati Open with a right knee injury, tournament organisers confirmed on Sunday, dealing another setback to the Italian’s preparations for this month’s US Open. The main draw of the Cincinnati Open starts on August 13, whereas the main draw of the US Open begins on August 30.