World No. 1 Jannik Sinner has withdrawn from the 2026 US Open after failing to recover fully from a right knee injury, dealing a major blow to the tournament ahead of its start.

Sinner confirmed his decision on Friday, saying he needs additional time to recover. The Italian had returned to court in Monte Carlo in recent days but felt that his knee problem had not healed sufficiently for him to compete at the year’s final Grand Slam.

The withdrawal comes just a day after defending champion Carlos Alcaraz announced that he would return to action at Flushing Meadows. Alcaraz has been sidelined since April with a right wrist injury and missed both the French Open and Wimbledon.

Sinner and Alcaraz were expected to be among the leading contenders for the US Open title. Their rivalry has produced several major encounters, including last year’s final, when Alcaraz defeated Sinner in four sets.

Sinner had enjoyed a successful season before the injury setback, winning Wimbledon earlier this year in Alcaraz’s absence. His absence from New York will now leave the tournament without its reigning world No. 1.

The Italian said he was disappointed to miss the event, particularly because of his strong connection with the New York crowd. However, he has opted to prioritize recovery rather than risk aggravating the injury.

Sinner’s withdrawal significantly reshapes the men’s singles draw, while Alcaraz’s return adds intrigue to the title race.