Argentina's Guillermo Coria, the world number three, has pulled out of the Olympic Games because of a right shoulder injury which could also rule him out of the rest of the season.
The 22-year-old Coria, who was runner-up to compatriot Gaston Gaudio at the French Open in June, returned to Buenos Aires on Wednesday having already withdrawn from the latest Masters event in Cincinnati.
"He will have further tests on the shoulder but he is ruled out and will not be going to Athens," said his physical trainer Christian Elseser.
Coria will be replaced in the Argentinian team at the Olympics by Mariano Zabaleta who won the recent tournament in Baastad, Sweden.
Teammate David Nalbandian is also a doubtful starter for the Games after an injured elbow forced him out of Cincinnati.
If he cannot play, Agustin Calleri will step in to join Gaudio and Juan Ignacio Chela the squad.