For the better part of a year, Hendricks was a human punching bag for Kampmann at the Xtreme Couture gym in Las Vegas.
Hendricks was one of the most decorated college wrestlers in decades, having won back-to-back NCAA championships in 2005 and 2006 before going 56-0 in 2007 during his senior year at Oklahoma State, only to lose in the finals.
He had his eye on a mixed martial arts career, but he didn't look particularly promising in those early days. He was knocked down repeatedly. He was punched and kicked and battered and beaten, hour after hour and day after day.
"It was such a huge learning curve," said Hendricks, who is 13-1 and now on the verge of a UFC welterweight title shot. "I got beat on by everybody. I don't remember which one beat me worse. It was a huge learning curve."
He found just as much of a learning curve in adjusting to his new surroundings in Las Vegas. There is a youthful, wide-eyed innocence to Hendricks, and he couldn't adapt to the fast pace and what he felt was the impersonal style of his adopted hometown.
After a year, he couldn't take living in Las Vegas anymore and moved his family to Texas, where he said he appreciates the neighbourliness as well as what he called the "Southern hospitality" far more.
In Las Vegas, he said, the people preferred to keep to themselves and not get too involved with their neighbours.
"I went next door to one of my neighbours to introduce myself, and the lady slammed the door right in my face," Hendricks said, explaining why he high-tailed it out of the Fight Capital of the World at the first opportunity.
But the move from Vegas had professional ramifications, as well as personal ones. As he improved and started to compete more evenly with Kampmann during their sparring sessions, Hendricks said he felt a distance growing between them.
"Once I got to a certain level, none of the guys trained with me at Xtreme Couture," he said. "I sort of got bumped to the back because they thought I was going to have to fight them one day."
If they did – though Kampmann and his coach, "Sugar" Ray Sefo dispute that – it turns out they were correct. Hendricks moved to Dallas and honed his game to the point where he's become one of the elite contenders for the welterweight title.
He's reeled off four consecutive wins, over T.J. Waldburger, Mike Pierce, Jon Fitch and Josh Koscheck, and on Saturday will meet Kampmann, his old training partner, in the co-main event of UFC 154 at the Bell Centre.
The winner has not been promised a title shot, though it's probably not coincidental that they're fighting immediately prior to the Georges St-Pierre-Carlos Condit main event.
In the three years since they split ties, Hendricks has gotten far better at striking, which is Kampmann's strength. Kampmann has gotten far better at wrestling, which is Hendricks' strength.
Neither disputes the contention that he helped the other with his weakness. But they do have vastly different views on what happened in that one year.
There's clearly an edginess between them that isn't open hostility, but also isn't all hearts and flowers.
As Hendricks talked about the development of Kampmann's game, he said Kampmann's improved wrestling was a result of the work they'd done together. But Hendricks knows that Kampmann isn't going to beat him by outwrestling him.
"I taught him how to wrestle," Hendricks said. "I showed him how to wrestle when I first got there. It's decent. Is it great? No. Is it on Josh Koscheck's level? No. Those are the guys I had to prepare for. Jon Fitch, is he on his level? No. I'm not so much worried about his takedowns. Do I know they're going to be there? Yes, I think he's going to try to take a shot to throw me off. I am worried about them, but I'm not worried about them, if that makes sense."
Kampmann, who has beaten Rick "Horror" Story, Thiago Alves and Jake Ellenberger in his last three, said Hendricks' was exaggerating his involvement in his wrestling improvement.
Asked directly if Hendricks taught him how to wrestle, Kampmann smirked.
"Nah, I think that's a pretty big overstatement, pushing the issue," Kampmann said. "I could wrestle before, but he showed me some good moves. He's a good wrestler. He's a two-time American champion, so of course I learned some wrestling from him. But I knew how to wrestle before that."
Sefo, who coached both of them, said they each were dominant in their own areas during their work together. Hendricks would routinely out-wrestle Kampmann, but Kampmann would always get the best of it in the stand-up, Sefo said. But Sefo disputed Hendricks' contention that the welterweights at Xtreme Couture wouldn't train with him as he improved.
"That's a false statement," Sefo said. "Martin, Jay Hieron, [Mike] Pyle, they all train together. We have three or four guys in the same weight class in the UFC and they've been there since Day 1. That's not necessarily true, and we've never really thought about it like that."
It all doesn't matter that much now, because as Kampmann pointed out, "We get to fight each other in a couple of days."
Kampmann has been a slow starter, though Sefo said he’s come out quickly in sparring in the last couple of weeks.
But Hendricks has the power to end a fight with one shot – he stopped Fitch with an overhand right just 12 seconds into their 2011 bout – and knows Kampmann may be most vulnerable early.
When someone suggested that Kampmann was durable, Hendricks sneered. Neither of them will admit to disliking the other, but Hendricks' words clearly made it sound as if he harbors some sort of resentment towards this ex-training partner.
"People are durable until they get hit," Hendricks said. "For example, [take] Jon Fitch. He was durable. Against GSP, he ate a lot of heavy shots. All it took me [to knock Fitch out] was one. If he's that durable, we'll really see. This is like the Jon Fitch fight. Everybody's like, 'Oh, he's so durable. Oh, he's going to do this. Oh, he's going to do that.'
"Dude, I don't care. Let me hit him one time. I can't wait to put my left hand right on his chin. Let's see where it goes from there. All I want to do is hit him one time. If he handles it, awesome, we're fighting. If he doesn't, guess what, it's over. That's my mind frame. I just want to hit him as hard as I can one time. One time and then [let's see] what happens."
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