Nelson told NBCSports.com that this isn't the first time the casual friends have trained together -- Nelson said he helped Mir prepare for a few fights "three-to-four years ago" -- but this is the first time Nelson has called upon Mir for a training camp.
"This one actually just fell in place. He was a southie, (like) Cro Cop, and me being a good jiu-jitsu guy, like Nogueira, so it was just a perfect fit," Nelson said.
"There's nothing strange about it. I think everybody in MMA, paths always cross, especially if you've been in this sport as long as we both have."
Of course, it would make sense for Nelson to align himself with Mir since Mir knocked out Cro Cop at UFC 119 last September. However, Nelson, nicknamed "Big Country," was quick to point out that other regular members of his "Country Club" have helped him train for Cro Cop -- Jose Salgado, R.J. Richter, Anthony Brown, James Johnson -- and he also spent time at Xtreme Couture in Las Vegas. He would not say whether Mir would corner him during the fight.
It's an important fight for Nelson (15-6) since he enters next weekend's bout stuck in a two-fight losing streak. He lost to Junior dos Santos at UFC 117 last August before losing to Mir in May.
And while he was criticized by UFC president Dana White for not being in good enough shape following the loss to Mir, Nelson figured out a way to do everything but answer how his physique will look next week.
"My hair has grown out a little longer. My beard is a little longer. So definitely, we're going to see a different Roy Nelson," he said.
But what about your weight, Roy?
"I just want to basically wow people with my beard, so definitely going for that."
You're not answering the question.
"As long as I'm 266, I'm good to go," he added.
"You know what? Everybody always talks about my weight, but that's throughout my whole entire life. It's nothing new. I'm sure everybody is going to talk about my weight next week, and then after my fight, and then my weight after that. It's just because people are mean."
Nelson did say he tipped the scales at 262 on Wednesday, so if nothing else, he will weigh the same as he last fought. As for what his body will look like, well, we'll just have to find out next week because Nelson was in no mood to spill the beans.
"To me, I look in the mirror every day, my wife thinks I'm beautiful, so I'm going to say probably not (look different)," he said.
"I hope I just perform better. Looks are in the eye of the beholder."