Tennis ace Nick Kyrgios I HAVE TO PUT LOVE FIRST

Grand Slams can't compete with hanging with his shorty!

- Helen Vnuk Florence Hartiaan Laura Masia

On the tennis court, Nick Kyrgios has beaten the world's best - Rafael Nadal, Roger Federer and Novak Djokovic included. But the famously hot-headed star knows his limits. When he took on the job of sideline commentator for reality TV favourite Australian Ninja Warrior, he didn't even think about giving the course a try.

"I would have fallen off at the first obstacle, which would have been incredibly embarrassing," Nick tells Woman's Day. “The first one is all about balance and core strength, and my balance is horrendous! You have to be a different breed to take on that course."

If he absolutely had to go head-to-head with another celebrity on the show, he says, "It would be hilarious to go up against someone like Lleyton Hewitt because the trash talk would be so entertaining. I think he'd beat me on most of the obstacles because he's smaller and has a lower centre of gravity, but it would be good comedic value for the fans.”

This is Ninja Warrior's fifth season, but the first time the Aussie tennis star has taken on sideline commentary duties, replacing English cricketer Freddie Flintoff in the role of talking to the ninjas just before and straight after they attempt the notoriously difficult course.