Former US Open finalist Kevin Anderson will not play at Flushing Meadows next week due to a right knee injury, the United States Tennis Association has announced.
World number 17 Anderson was beaten Rafael Nadal in the 2017 final in New York, while he lost at the same stage at Wimbledon to Novak Djokovic in 2018.
But the South African's hopes of a breakthrough grand slam title have been ended for another year after he was forced to withdraw from the US Open two days before his tournament opener.
Anderson has played just 15 matches on the ATP Tour this season and has not featured since Wimbledon.
He had been drawn as the 16th seed at Flushing Meadows, but lucky loser Paolo Lorenzi will take his place against 16-year-old American Zachary Svajda.