Bare-knuckle boxing is coming back to Wyoming this fall, and a pair of well known UFC veterans will take center stage.

Longtime UFC star Chris Leben (22-11 MMA) and Phil Baroni (16-18 MMA) have signed contracts to fight at an Oct. 20 event in Casper that’s being promoted by World Bare Knuckle Fighting Federation (WBKFF).

The announcement comes one month after another promotion, Bare Knuckle FC, drew an estimated 2,000 fans to watch several UFC vets slug it out sans gloves. Although a venue has not been finalized for October’s event, negotiations are underway for the 8,000-seat Casper Events Center to host. WBKFF’s inaugural event will air live via internet pay-per-view.

Leben’s signing comes three years after an MMA comeback in Bellator was nixed by a severe condition that left his heart pumping a dangerously low level of blood. Doctors said Leben’s left ventricle had a “life-threatening abnormality” and estimated blood flow to the heart was “only 18 percent of what is considered normal.”

In an interview today with MMAjunkie just hours after signing his WBKFF contract, Leben said the actual percentage of his ejection fraction – or the measurement of the percentage of blood leaving the heart each time it contracts – was even lower at 14 percent. Through diet and lifestyle changes, including strict abstinence from alcohol, he said he was able to bring his heart back to normal function.

“For the last three years, I’ve been sober, and I’ve also been on an organic supplement regimen that my boss at (Arena MMA) put me on,” Leben said. “Things like raw cayenne pepper, raw garlic powder, turmeric, wheatgrass – I take about 20 different powders a day, a couple times a day.”

Leben’s history with illicit substances is well known. His condition was thought to be the result of years of struggle with drug addiction, including “extreme opiate addiction” and alcoholism as well as “medical and psychological issues throughout his life.”

Now Leben says he lives a low-stress, healthy life that’s enabled him to give more in the gym.

“My cardiologist is in disbelief,” he said. “They didn’t expect me to ever recover, much less to the level I’m at now, where I’m just like another healthy adult again.”

Leben said his doctor actually cleared him to fight one year ago, but he chose to give himself an additional 12 months to see if his body adjusted to the rigors of training. He said another checkup this past week returned even better results on his blood flow, and the doctor declared he couldn’t improve any more.

“I feel better than I ever have,” Leben said. “I was probably running on four cylinders my last few UFC fights, and now I’m going to be able to go out there and put 100 percent out. Not to mention, my head is about 1,000 percent clearer. I feel dangerous.”

WBKFF director of operations and events, a man who identified his full name as “J.C.,” told MMAjunkie that Leben reached out to the promotion about appearing on the card, and a deal was quickly struck. He said the event will be sanctioned by the Wyoming Combat Sports Commission, which will review the matchups for approval. Fighters will be required to submit medical tests for clearance.

Asked whether he had any concerns about signing Leben based on his medical history, J.C. said the promotion aims to take every step necessary to ensure fighter safety.

“If Chris and his medical team and our medical team can come to the conclusion that this is OK, then no problem,” J.C. said. “I don’t think Chris would put himself in harm’s way, or get himself hurt in any way, and I don’t think his medical team would allow that either.

“I don’t care how much money you pay somebody, but the goal here is not to pay someone a bunch of money, and if they get hurt, or risk major death or injury of some sort, oh well. That’s not what this is about. So we’re going to cross all of our t’s and dot all of our i’s in regards to everyone’s medical condition, and that includes Chris and Phil and everyone we sign.”

Phil Baroni (red gloves) in 2015 fighting for ONE Championship.

For both fighters, the opportunity to jump in the ring not only offers competitive intrigue, but a healthy payday to boot. Baroni told MMAjunkie he received the call to fight Leben earlier today while using the bathroom.

Baroni said his words after he heard the payout were, “(expletive) yeah.”

After a four-year layoff, Baroni started his own MMA comeback in May. He was unaware of Leben’s heart troubles and was surprised given the former UFC star’s endurance in fights.

Baroni hopes Leben’s issues are resolved. At the same time, he predicts his punching power will end the fight early.

“We were supposed to fight a long time ago,” Baroni said. “I had an offer when I was in PRIDE to come back and fight Chris by (UFC President) Dana White. He was doing the gimmick with the ‘TUF’ show, but I stayed in PRIDE, so it never happened.”

But with pen to paper, that’ll change in October.

For more on the upcoming MMA schedule, check out the MMA Rumors section of the site.