That doesn't mean the UFC heavyweight contender didn't brutalize anybody inside of an octagon after he ran afoul of Nevada's doping policy.
"I hurt all of them," Overeem said of his sparring partners. "I crushed their souls."
Overeem — who takes on Antonio Silva at UFC 156 in Las Vegas on Saturday — may have been half-joking, but there was a lot of truth behind it. Mario Sperry, his coach with the Blackzilians camp in Boca Raton, Fla., said Overeem dinged each of the 15 or so fighters he trained with since the Dutch Muay Thai specialist arrived at the gym in March.
"I would say probably all of them got injured in one way or another," Sperry said. "There were some guys he sparred with who didn"t come back for a week or two. He knocked out a few guys who couldn't come back for a day or so. Pretty much everybody got hurt, including me."
Overeem has fought just once in the last 18 months and that bout took all of two minutes, 26 seconds. It was Overeem's UFC debut and his TKO in December 2011 sent former heavyweight champ Brock Lesnar into retirement.
A May bout against then-champ Junior dos Santos was up next, at least before Overeem was found to have elevated levels of testosterone in an out-of-competition test before the bout. Overeem said something that a doctor prescribed to him led to the exceedingly high testosterone levels.
Overeem told the Nevada State Athletic Commission in early January that he's done everything he can "to correct the errors" that led to the positive test. The commission voted unanimously to approve his license, clearing his return to the UFC.
He told FOXSports.com that he "would do anything the UFC or the commission asks" in terms of testing in the future.
"I'm no longer in touch with that doctor," Overeem said. "I have a new protocol where I double check everything that goes into my body. This isn't going to happen twice. I'm not making another one of these mistakes."
Despite assurances of people around him that he'd be cleared to fight once he was able to re-apply for his license in December, there were no guarantees. A ruling on a license in one state is observed by every other state commission and UFC management would be very reluctant to allow a fighter serving what amounts to a drug ban to fight on one of its cards abroad.
"I tried to make the best of the situation," Overeem said. "I surely didn't want this situation, but I continued to train every day. I improved every part of my game. I got to know my new city, Miami. I had just moved there. I shook a lot of hands and met a lot of new people from the management (of the gym) to sparring partners."
"I was investing in new relationships. The time off was great. When you are a fighter in camp, you can't be social. I had some time to go for dinner or go out for a drink."
Sperry said that despite the lack of a guaranteed return date (the UFC 156 being contingent upon reinstatement), Overeem remained focused and was the same brutal fighter that has seen all but two of his 36 pro wins end in stoppages.
"Whenever he trains, he trains hard. That's his style. It's something he did in K-1 and Pride. He trains like he fights. Whenever he touches you, it hurts. He can get you with kicks and elbows, even when he"s on the ground."
One of the few fighters who wasn't injured — at least beyond a couple bumps and bruises — at the Jaco Hybrid Training Center was Tyrone Spong, a Muay Thai champ making the transition to MMA. Spong made his MMA debut in November and knocked out Travis Bartlett in the first round at a World Series of Fighting event.
"You don't have to push him," Spong said. "He always wants to work. He's always looking to try new stuff to improve his game."
Spong added that Silva shouldn't expect any rust come Saturday.
"I can imagine this made (Overeem) hungrier and more eager to perform," Spong said. "I think that (the layoff) was something he took personally."
Overeem said he's not looking past Silva, a major underdog who most recently beat Travis Brown in October to end a two-fight skid. Still, he doesn't expect the fight to take long.
"I'll be finishing it in the first or the second round," Overeem said. "It's not going beyond the second."
With a victory, the most likely challenger would be dos Santos — at least if he doesn"t get an immediate shot at champ Cain Velasquez. But an Overeem-dos Santos card could be hard to pass up with the vitriol already flying.
Dos Santos — who had lobbied UFC president Dana White to fight Overeem — questioned if Overeem fights without the assistance of banned substances and called his performances "fake." Overeem wrote on Twitter that dos Santos "looks pretty" with a swollen face after Velasquez eased to a decision to reclaim the title in December.
Whoever it is, Overeem is just eager to fight.
"My optimum number is three times per year," Overeem said. "I'd really like to fight three times this year — maybe even four."
It's a sentiment probably shared by his training partners.