UFC middleweight champion Robert Whittaker isn’t one to complain, but he admits he was pretty upset when he was forced to withdraw from a planned title defense in his adopted home nation.

“I’ve never pulled out of a fight before due to injury,” Whittaker told MMAjunkie. “When I was headlining in my own country, it was very hard for me to get around that fact that I was going to have to pull out of this one. It didn’t sit well with me.

“I’m not one to pull out, but it is what it is. … I’ve had a lot of good fortune, so getting sick now and then can’t be helped.”

Truthfully, it wasn’t actually an injury that forced Whittaker out of a planned matchup with Luke Rockhold at February’s UFC 221 event in Australia. First, it was staph infection – and later chickenpox.

That’s right. Chickenpox.

“Chickenpox was by far the worst thing I’ve ever had,” Whittaker said. “I’ve never had it before, and it was absolute hell. They became blisters, and they were all over my body. It was the worst thing I’ve ever had. It was unreal. … When you’re an adult and you get chickenpox, it’s absolutely terrible.”

In the meantime, Yoel Romero – who Whittaker defeated last July at UFC 213 – stepped in to face Rockhold with an interim title on the line. When Romero missed weight, he became ineligible for the belt, but still went out and delivered a brutal knockout.

While gutted he couldn’t fight on the card, Whittaker said he wasn’t upset one bit at the UFC’s decision to put an interim title on the line.

“To be honest, I was delighted,” Whittaker said. “I was happy because they gave me the time I needed to get better, and then they pitched my No. 1 and No. 2 contender against each other, which is great. If all my contenders can just bash each other for the meantime while I’m getting better, that would be great.

“As a fan, I was really interested in seeing that fight. I was really curious to see how Yoel would go up against Rockhold, and vice versa. Yoel didn’t make weight. That was unprofessional, at best. You can make all the excuses in the world, but at the end of the day, if you ruck up and you’re not on weight on the scales, you haven’t done your job.

“To see Yoel starch Rockhold like that was just crazy, especially with Yoel not fighting like he does normally. He came out with a completely different gameplan.”

Now Whittaker (19-4 MMA, 10-2 UFC) and Romero (13-2 MMA, 9-1 UFC) will meet again in the main event of UFC 225, which takes place June 9 at United Center in Chicago and airs on pay-per-view.

It doesn’t seem like much of a reward for Whittaker. After all, Romero remains one of the scariest fighters in the UFC, and after just beating him last time out, Whittaker now has to do it again.

But the 27-year-old Australian resident believes Romero has absolutely earned the opportunity.

“Who’s left to fight him that he hasn’t already beaten in the top five?” Whittaker asked. “I think he’s definitely solidified his place as No. 1 contender. It’s hard not to with him just tearing through absolutely everyone until he got to me.

“I’ve never been one to pick and choose fights. I’m happy to fight whoever is in the No. 1 spot. That seems to be Yoel right now.”

Whittaker will have the benefit of their first fight, in which he suffered an injury to his leg but still gutted his way to a decision win. But Whittaker knows he’s still facing an incredibly dangerous opponent.

“I took confidence in that I knew I could face adversity in a fight and get over the line,” Whittaker said. “But I’m under no illusion that this fight isn’t 50-50 still. He’s an amazing athlete. He’s an amazing fighter, and he was hella annoying to fight the first time, so I’m looking forward to a real annoying fight the second time.

“I’m doing everything in my favor to stack the chips on my side, and I’m going to get in there and give him hell.”

Eleven months after they first did battle, Whittaker and Romero will run it back at UFC 225. Whittaker’s tenacity and durability certainly impressed the first time around, and doing it a second time – especially when no other UFC fighter has done it even once – would prove an even more amazing feat.

“Every day I go to the gym, and I increase my skillset,” Whittaker said. “I strive to become the best fighter that I can be. I feel that every time I step into the octagon, I’m showing that – I’m showing a better version of myself. I’m showing the skillsets that I’m gaining. With that mentality, I made it all the way to the top, and I have that mentality now. The No. 1 contender is going to show up, and I’m going to fight him. I may win, I may lose, but I’m doing the right things.

“If you want to see fireworks, make sure you tune in and watch me and Yoel go at it.”

For more on UFC 225, check out the UFC Rumors section of the site.