London - World number one Serena Williams admitted it was a sad day for the Olympics on Tuesday after Jason Day, the world's top-ranked golfer, joined the growing legion of stars turning their backs on Rio.
Australian Day said he would not compete at the Olympics in the Brazilian city in August due to fears over the Zika virus.
Hours later, Ireland golfer Shane Lowry also said he would snub the Games.
"I think it is sad," said Williams, after reaching the second round of Wimbledon.
She insisted it remains her intention to go to Rio where she will be the defending champion.
"I obviously understand where they're coming from and how they feel. Part of me feels that way, too, which is why I'm going in with a whole mindset of how do I protect myself and also raise awareness for this," she said.
Williams said she had never contemplated pulling out of the Olympics.
The Rio tennis tournament has, however, already suffered a number of withdrawals.
John Isner of the United States, Austria's Dominic Thiem, Australian duo Bernard Tomic and Nick Kyrgios as well as Spanish veteran Feliciano Lopez have all opted, for various reasons, not to take part.
"I don't know if they're missing out. I mean, everyone's experience is different. My experience has been really amazing at the Olympics," said Williams.
"It's difficult for someone that's in a sport like golf because their main goal, like tennis, is to win slams.
"But for me, I look at the Olympics as a bonus opportunity. It's probably one thing (the gold medal) I have that I love the most."
Williams reached the Wimbledon second round with a 6-2, 6-4 win over Swiss qualifier Amra Sadikovic as her mother watched from the front row of the Royal Box.
The 34-year-old world number one, chasing a seventh Wimbledon title and record-equalling 22nd major, took her Grand Slam career record in first rounds to a formidable 63 wins against just one defeat.
She next faces fellow American Christina McHale for a place in the last 32.
"My mom was up there in the Royal Box, so that was nice," said the American star after giving mother Oracene Price an afternoon to remember on Centre Court.
"I will have to get my dad out here now."
Williams claimed victory over world number 148 Sadikovic on a second match point courtesy of a successful Hawk-Eye challenge.
"I never underestimate any opponent. I always expect the best of myself," added Williams, who won 12 straight points at the start of the match and now has 80 match wins at the All England Club.
However, not everyone gave her the royal seal of approval.
"It was one of the worst serving efforts I've seen from Serena. This is what is giving other players hope," said US legend John McEnroe, commentating for the BBC.