Zika virus a concern for 'super protected' Serena

Serena Williams said on Saturday the health dangers posed by the Zika virus in Rio ahead of the Olympics are a serious concern, while Novak Djokovic pleaded for the impact on Brazilians not to be underestimated.

"It's something that's been on my mind. I'm really just gonna have to go super protected," said Williams, the defending Olympic champion, after making the last-16 of the French Open with a 6-4, 7-6 (12/10) win over home hope Kristina Mladenovic.

An open letter addressed to the World Health Organization (WHO) signed by 150 international doctors, scientists and researchers on Friday called for the August Games to be moved or delayed to help prevent the spread of Zika.