Robert Whittaker has detailed the illness that knocked him out of the UFC 221 main event.

Whittaker was originally scheduled to defend his UFC middleweight title this Saturday night (Feb. 10) against Luke Rockhold. A staph infection ruled Whittaker off the card. Rockhold will meet Yoel Romero for the interim 185-pound title.

During a recent appearance on “The MMA Hour,” Whittaker went in-depth on what went wrong:

“I think a lot of my fans and a lot of the general populace know that I have no qualms with going into a fight injured. I’ve gone into many fights injured. I went into the Yoel Romero fight with a torn MCL, I went into multiple fights with broken hands, and that’s never deterred me. And during my prep and my camp, I did my hamstring — I did blow my hamstring out — but I was willing to work around it. So we just worked around it, threw it on the wall, no explosive sort of stuff, and then I got an abscess infection.”

“The Reaper” had to take antibiotics for weeks, but things just got worse from there.

“That absolutely knocked me out of the park. I was on antibiotics for that for weeks and it was just really getting out of hand, and we were still — we were still very much, ‘Oh, we can make this work. If we cut out the three weeks we’ve lost now, we can turn it around so that we can just focus on fitness and skill sets and just get it done.’ And at the end of that, when I was thinking maybe we’re not able to fight, I got chickenpox as well. It was the sickest I’ve been in my entire life.”