Paris - Rafael Nadal said he cannot understand why a host of players are snubbing the Olympics, "the most important event in the world of sport".
Nadal won gold at the Beijing Olympics in 2008 but a knee injury prevented him from defending his title in London four years later where he was also due to be Spain's flag-bearer at the opening ceremony.
"The Olympic Games is the most important event in the world of sport," said Nadal after reaching the third round of the French Open on Thursday.
"I cannot understand people who don't want to go to Olympics. It's an event that you can compete only once, twice, or three in your career maybe, if you are lucky. So you don't want to miss that."
So far, 17th-ranked John Isner of the United States, Austrian 15th seed Dominic Thiem, Bernard Tomic, the world number 22 from Australia and Spanish veteran Feliciano Lopez, 23 in the rankings, have all announced they are giving the Olympics in Rio in August a miss.