Carlos Alcaraz's ability to defend his US Open title is in serious doubt after he withdrew from the upcoming Cincinnati Open, extending an absence caused by a wrist injury that has now kept him out of competitive tennis for 114 days. The 22-year-old, who completed the career Grand Slam in January by beating Novak Djokovic at the Australian Open, has already missed the French Open and Wimbledon, and experts warn wrist problems are notoriously unpredictable and difficult to recover from fully.

Alcaraz is suffering from tenosynovitis, an inflammation of the tendon sheath in the wrist typically caused by the repetitive gripping and swinging involved in tennis. He has avoided surgery, but the injury has kept him sidelined for over four months, part of which he spent unable to hold a racquet. Specialists note that wrist injuries are becoming more common in the sport due to more powerful equipment, harder-hitting play and gruelling schedules, with former players such as Dominic Thiem and Juan Martin del Potro having suffered similarly persistent wrist problems throughout their careers.