Nadal is one of the first major sports figures to compete in the city since Brazil became the focal point for the virus that has spread rapidly across the Americas. Health officials believe it is linked to microcephaly, a condition marked by abnormally small head size that can result in developmental problems.

Despite a recent surge in reports of infants born with these birth defects in Brazil’s northeast that world health officials say is likely linked to the mosquito-born virus, Nadal, who has qualified for the men’s singles tennis event at the Games, said the situation in Rio “was not likely to be so serious.”

“I see people conducting their lives normally… I see people walking, people on the beach, people in restaurants, people having completely normal lives,” the world’s former top player Nadal told reporters at the Jockey Club, which is hosting the Rio Open.

Several athletes and visitors planning to come to the Olympics have expressed concern about Zika, which has been reported in more than 30 countries, according to the World Health Organization.

There are currently no vaccines or treatment for the virus, though research institutes and pharmaceutical companies are working on several possibilities.

(Reporting by Pedro Fonseca; Writing by Reese Ewing; Editing by Alan Crosby)