Caroline Wozniacki joined Ronda Rousey and Lindsey Vonn as among the athletes to boldly pose naked, their private parts only covered by body paint, in the swimsuit issue of Sports Illustrated.

The world's no. 19th shared that she felt "totally naked" even if she's covered in body paint. Nevertheless, Serena Williams' BFF is glad she went through with the photoshoot.

"I feel totally naked. But when I look in the mirror, it's the weirdest thing - I feel like I have plenty of clothes on," she said in the BTS clip.

"It's kind of a surreal experience. I have never done anything like this before, so it makes it very special," she said.

"Knowing what an incredible suit I have on right now, and we are in the most beautiful place here so I am sure the photos are going to be amazing."

According to the Irish Independent, Caroline Wozniacki's Sports Illustrated shoot was very gruelling.

"In a behind the scenes video released by the magazine," it said. "They show the painstaking effort that goes into making the former world number one feel picture perfect, including the 15 hours of bodypaint application it took to get a lifelike looking swimsuit."

What's worse was that Caroline Wozniacki had to stand all throughout the application of body paint for the Sports Illustrated issue.

"I love my body paint, and it has been such an unbelievable experience, really," she said.

The latest Sports Illustrated photoshoot proved that Caroline Wozniacki is branching out her brand from tennis, and also moving away from being known as Rory McIlroy's fiancee. The golfing star broke up with the tennis player in March 2014.

"I am so much further along in my life, and I'm so much happier now," she told Page Six.

"I don't think there is a reason to go back. Obviously, that relationship taught me so much and made me the person I am today, but at this point, I am like, I've moved on, Rory has moved on, and I am ready for the media to move on."