World number one Jannik Sinner has withdrawn from this week's Cincinnati Open due to a right knee injury, though he still expects to be fit for the US Open later this month. The 24-year-old Italian, who has not played since beating Alexander Zverev in July's Wimbledon final to claim his fifth Grand Slam title, said he had consulted his medical team but was "not ready to compete yet".

The Cincinnati Open runs from 13 to 23 August, with Zverev and 24-time Grand Slam champion Novak Djokovic among the players competing. Defending champion Carlos Alcaraz, who beat Sinner in last year's final after the Italian retired through illness, will also miss the tournament because of a wrist injury that has kept him out since April. The US Open, the season's final Grand Slam, takes place in New York from 30 August to 13 September.