World number six Robin Soderling has been forced to withdraw from the US Open just hours before his first match.
The 27-year-old, who was due to take on Irish qualifier Louk Sorensen this afternoon, made tournament officials aware that he would be unable to compete because of illness.
The Swede's place has been handed to Rogerio Dutra da Silva of Brazil.
Soderling's illness has yet to be disclosed.