World No 1 and Wimbledon champion Jannik Sinner has been ruled out of the US Open due to a knee injury. Sinner, US Open champion in 2024 and last year’s runner-up, confirmed the decision in a statement on social media. The Italian’s withdrawal comes as rival and defending champion Carlos Alcaraz makes his comeback from a wrist injury following four months out. Sinner has not played since defending his Wimbledon crown and winning his fifth grand slam title by beating Alexander Zverev in July. The 25-year-old did not appear to be hampered by injury during the tournament, apart from when he slipped on the grass during his round-one win over Miomir Kecmanovic. But alarm bells were raised when he skipped his second successive ATP Masters tournament and pulled out of the US Open warm-up event in Cincinnati. “Even though I have been working hard with my team and my medical staff, we have now had to make the difficult decision that I will not be able to compete at the US Open this year,” Sinner said. “We have been back on court in Monte Carlo over the last couple of days and have realised that I still need more time to recover from my right knee issue. “I’m obviously very sad and disappointed, as New York has a special place in my heart. I was very much looking forward to coming back and playing in the electric atmosphere in front of the great fans there.” Alcaraz defeated Sinner to win last year’s US Open (Getty Images)Sinner’s injury is the latest blow in what has been a deeply strange season of men’s tennis since the Australian Open at the the start of the year. Alcaraz missed both the French Open and Wimbledon due to his wrist injury while a number of top young players, such as Jack Draper, Arthur Fils and Holger Rune, have also suffered injury issues. Zverev won his first grand slam title at the French Open by beating Flavio Cobolli in the men’s final, before Sinner defeated the German to defend his Wimbledon crown the following month while Alcaraz’s absence was again felt. Alcaraz has not played since April and will enter the US Open aiming to defend his title in what appears to be a wide-open tournament. Novak Djokovic, who suffered a surprise second-round defeat at the Cincinnati Open, may believe that this is another golden opportunity to a win a record 25th grand slam title.