Speaking exclusively to EPSN Australia, Robert Whittaker says that his winning gameplan is unchanged heading into his second fight with Yoel Romero. (0:43)

It has been an eventful 12 months for UFC star Robert Whittaker but nothing has shaken his desire to be the best fighter ever, even if that means getting back into the Octagon with a man he said "hits like a truck."

Whittaker will defend his middleweight crown on June 9 against the same man he won the interim belt from 11 months ago, Cuba's Yoel Romero. The Australian was then crowned the UFC's middleweight champion when Georges St-Pierre vacated the belt for health reasons in December.

Since then, Whittaker has fought a staph infection that became chicken pox, was named to headline the UFC's historic debut in Perth and then had to withdraw, before he again rode the highs and lows of sport with selection to Australia's Commonwealth Games team. That also ended in disappointment with his withdrawal from Australia's wrestling squad. The reason? A rematch with Romero at UFC 225 in Chicago.

So what does he take from the points-decision in Las Vegas last year?

"Some people ask me: Does it give you any confidence knowing that you've already beaten him once? I've got to say 'not really' because he hits like a truck and it only takes one to get you," Whittaker told ESPN.

"He's a human specimen to begin with and he's one of the most athletic, explosive and talented humans on the planet. So every time I step in there with him it's 50/50."

The stats from their previous battle in Vegas are telling. Romero landed more strikes -- 114 to 94 -- but it was Whittaker who delivered the better blows as shown in the 74-48 significant strike count.

Somewhat surprised by those stats, Whittaker takes a moment to recall Romero's tactics and an "annoying" approach to be wary of this time around.

Robert Whittaker [L] takes Yoel Romero down in their first fight in Las Vegas Jeff Bottari/Zuffa LLC/Zuffa LLC via Getty Images

"Yoel had a higher strike count? Did he have a higher strike count? Oh, I think they counted all the little knuckle things that he did on the ground," he said. "They were painful, they were stupid. They were like these little wrapping of the knuckles on my skull, and it was just annoying, it was so annoying.

"He wouldn't have stopped me with it but it was just annoying. It was just like, you remember when you played knuckles as a kid? It was just like that on my head."

While Whittaker has no complaints about his preparation for Chicago, the bout of chicken pox that forced him to withdraw from Perth was brutal.

Renowned for being far worse when contracted as an adult, the virus took a serious physical toll.

"From the start of the staph to the end of the chicken pox, it was close to two months because they both went their full term," Whittaker told ESPN. "The chicken pox just weren't [disappearing] and you can't go training with open blisters; no one wanted to come near me.

"It definitely took a toll because you can't train with fevers; I couldn't do any physical training. But as soon as I was well enough to get back in there and start doing stuff, I started with some cardio stuff that didn't require me doing physical contact. I did some conditioning stuff and then slowly built up from there."

While he couldn't fight in Perth, Whittaker was a keen spectator as Romero floored American Luke Rockhold with a devastating right hand. But it was a controversial victory, after the Cuban had missed weight in the lead-up.

play 1:57 Whittaker: Beating Romero once doesn't give me extra confidence Speaking exclusively to ESPN Australia, Robert Whittaker discusses his previous fight with Yoel Romero that saw him win the UFC middleweight championship, and what effects it has on him as he prepares to face him again.

"I think you do have to get on with it and move on, that's the inevitable outcome," Whittaker said when asked about a fighter who fails to make weight.

"But it makes me upset. It would make me upset if my opponent missed weight because I believe making weight is half the job; if you don't make 84.5 [kilos, 186 pounds] then we're not in the same weight division. I don't even know how that's [missing weight] a thing?

"If we're not the same weight, we're not the same weight; we're in different weight divisions. It's ridiculous to think about it."

What isn't ridiculous is Romero's ability to finish a fight with a single strike, just as Rockhold discovered in Perth. Given the experience of "knuckles" from last year, it means Whittaker has plenty to ponder when the bell rings in Chicago later this week.

Robert Whittaker [L] and Yoel Romero face off at a UFC promo event in Brooklyn Jeff Bottari/Zuffa LLC/Zuffa LLC via Getty Images

"I'm constantly pushing my mental capacity well over its cap," he said. "I'm thinking about his takedowns; I'm thinking about not getting hit with his sledgehammer hands. I'm tired, I need to initiate the attack; I have to push him, he has to push me. That, for 25 minutes, it takes a toll. It's more mentally taxing than physically taxing."

Asked about a prediction, Whittaker said it's about doing whatever he possibly can to win for every second of the 25 minutes the duo will stand toe-to-toe inside the Octagon.

But his belief in the ultimate goal is unwavering.

"I want to be the best fighter ever, there ever was, there ever has been; there ever could be. And the only way I can do that is by fighting everyone and just stopping everyone."