(ANSA) - ROME, AUG 21 - Jannik Sinner will not play the upcoming US Open with the five-time slam winner and world number one saying Friday he was pulling out due to a knee injury. "Despite the hard work done with my team and the medical staff, we have had to make the difficult decision not to participate in this year's US Open," a statement from the two-time Wimbledon and Aussie Open winner and one-time US Open winner read. In recent weeks, Sinner had undergone regular check-ups between Milan...