Ali Abdel-Aziz picked up the phone and started dialing a few months ago. He called just about every member of World Series of Fighting's lightweight division.

Did they want a title shot? Absolutely. Were they willing to beat three men in one night to do it? Well, that wasn't as easy a question to answer.

Eight men did accept the offer, though, and they will be competing Friday night in an old-school, one-night tournament at WSOF 25 in Phoenix that will air live on NBC Sports Network. There will also be one alternate bout. The tourney winner takes on lightweight champion Justin Gaethje on a future card.

While WSOF has essentially the best fighters in its 155-pound weight class competing, Abdel-Aziz, the promotion's executive vice president, said not everyone he called was willing to run this kind of gauntlet.

"It's a different breed of man that wants to be in this tournament," Abdel-Aziz said. "I'm not saying the other guys are not great fighters. They are great fighters. I think it takes more than being a fighter to be in this tournament. It's a lot of courage. It's a lot of -- I don't want to say a lot of balls, but it is. It's a lot of balls. It's intense."

There's no doubt about that. There's a reason why one-night tournaments -- especially of the eight-man variety -- have mostly gone the way of the Dodo bird. Athletic commissions have shied away from sanctioning them. Doctors have denounced them. In an era of increased regulation, adding more fights -- and more rounds -- to an athlete's night can be deemed as controversial.

WSOF and the Arizona Boxing and MMA Commission will take steps with fighter safety in mind Friday night. The quarterfinals of the tournament will be only two rounds, rather than three. Elbows will be banned until the finals. Those alternate bouts are in place in the event of one of the winners (or losers) not being healthy enough to continue. An alternate will only be used if both the winner and loser of a matchup cannot advance due to injury concerns.

Arizona Boxing and MMA Commission executive director Matthew Valenzuela told MMA Fighting that the number of physicians on hand Friday will increase from two to three and there will be ample time in between tournament rounds for fighters to recover.

"After every fight, we do post-bout physicals," Valenzuela said. "There's time in between the bouts because we have the two or three doctors available, the fighters can be looked at to make sure there's no after-the-fight injury. It takes about 20, 30 minutes if someone is concussed -- there's usually vomiting, headache, nausea. Stuff like that. A doctor would be advising us as to whether they can compete or not."

Some in the regulation community don't believe that even those precautions are enough. Multiple athletic commission directors told MMA Fighting that they would not sanction such a tournament due to safety risks. Former ringside physician and neurosurgeon Dr. Margaret Goodman, now the president of the Volunteer Anti-Doping Agency (VADA), said she has "great concerns regarding same-night tournaments in combat sports."

"Fighters have sufficient risks fighting once in a night and fighting more often sets them up for Second Impact Syndrome," Goodman said in an e-mail. "SIS is a known, often-deadly condition where an athlete suffers what seems to be mild trauma -- and may even be asymptomatic for a concussion -- but experiences a second impact minutes to hours or perhaps a day or so later. The second impact may also be minor, but it results in a cascade of changes within the brain, producing rapid brain cell death."

Abdel-Aziz understands the implications, but maintains that "at the end of the day, this is a fist fight." He and WSOF president Ray Sefo have also pledged from the start of the promotion in 2012 that fighters are of the utmost importance. That, Abdel-Aziz said, will not change going into this tournament.

"We're gonna make sure fighters are healthy before they move on," he said. "And guess what? The number one here at World Series of Fighting, we always say fighter first. And fighter safety will come first. If a guy wants to fight and the doctor said he can't fight, guess what? He's not gonna fight. He can fight another day."

Tournaments are not a new idea in MMA, of course. The sport was built on them. UFC 1 was an eight-man, one-night tournament and the UFC ran with that format for years. PRIDE's tournaments were the stuff of legends. Sefo, himself, has competed in countless one-night tournaments in kickboxing. Abdel-Aziz, also a life-long martial artist, wants WSOF to bring them back to the forefront, running one to two per year.

"When MMA first started to become popular, it was the eight-man tournament," he said. "It was all about the last man standing. Today, everybody knows who Royce Gracie is. Everybody knows who Dan Henderson is. Mark Coleman. All those guys have won one-night tournaments and all of them are legends. When you create a tournament like this, it's not only going to have some great fights, you create stars. You have the fans get attached to the one guy they're rooting for throughout the night. And if the guy wins, he has fans for life. Even some of the guys that lose, they have fans for life."

Roan Carneiro is a good example of that. Battlegrounds MMA ran the first major eight-man, one-night tournament in nearly a decade in October 2014. Carneiro won it, was signed by the UFC soon after and promptly beat long-time middleweight contender Mark Munoz back in February. Abdel-Aziz said the tournament "revived" Carneiro's career.

Bryan O'Rourke, the Battlegrounds promoter, would not disagree with that. He also takes pride in the fact that both Bellator and now WSOF have run one-night tournaments since he brought the format back last year. However, O'Rourke said he lost more than $300,000 on the card and he's currently in a financial dispute with his pay-per-view distributor, Integrated Sports Media. There hasn't been a Battlegrounds event since.

"To me, it proves the concept for those larger promotions to do it," O'Rourke said. "And I like that. I had a great idea, I executed the idea. I held the first legal tournament in like [a decade]. I think that's a win. But I'm also not a moral victory kind of guy. If I could have half a million dollars back, I'll take my half a million dollars back."

Battlegrounds was held in Tulsa and sanctioned by the Oklahoma State Athletic Commission. All three possible fights were three rounds and, like WSOF, elbows were illegal until the finals. OSAC added additional medical testing, like neurological exams before and after each fight done by a specialist, and had four physicians on site.

Bellator's tournament was on a smaller scale. At Dynamite 1 in September in San Jose, Bellator held a four-man, one-night tournament. The semifinals were two rounds and the finals were three. It's California law that an MMA fighter cannot compete for more than five rounds in a given day. An injury kept Muhammed Lawal out of the final at Dynamite and alternate Francis Carmont took his place, falling to Phil Davis.

Bellator president Scott Coker has expressed an interest in one-night tournaments moving forward. Meanwhile, WSOF is going all in. The promotion wants to make them part of its brand.

"It's history," Abdel-Aziz said. "It's reminding the fans how we started this thing. We're just picking up the torch. [The UFC] stopped doing it. We're gonna keep doing it. This is not gonna be our last tournament. This is just the beginning."

There's no doubting the popularity of tournaments. March Madness is one of the most popular sporting events in the world. The playoff system in most team sports is based off brackets. Abdel-Aziz also loves the fact that a fighter has to earn -- rather than be gifted -- a title shot with a grueling victory.

"There's no politics," he said. "The toughest man will win. Whoever wins the tournament gets a title shot. There's no favoritism."

The tournament will feature legitimately high-level fighters, too. UFC veterans Brian Foster and Mike Ricci are in the mix. So is prospect Islam Mamedov. Luis Palomino, considered a tournament favorite, has already fought Gaethje twice this year, but both bouts were absolute thrillers.

The intrigue will certainly be there. Hopefully, the increased safety measures will be effective, too. Abdel-Aziz is confident.

"Americans and people around the world, they love brackets," he said. "They love the Olympics. The Olympics is about brackets. People somehow, they think brackets are sexy. We're just bringing sexy back. That's all we're doing."