For Antonio McKee and his son A.J., fighting has been a constant, a presence as real as a family member. As a youth, Antonio was a wrestler who struggled with his temper and would occasionally turn a match into a fight. As an adult, he turned professional, fighting at hotels and fairgrounds and any other place promoters would put up a cage. Two decades later, he’s still in the business. He runs a successful if underrated fight team, the BodyShop, in Lakewood, Calif., and these days, it’s his son that is his top protégé. In fact, many believe that A.J. is on the cusp of stardom, with the opportunity to break through during Bellator’s featherweight World Grand Prix.

It’s a journey they’ve taken together on two different levels, as father-son and coach-pupil. At Bellator 228, they’ll experience it in yet another way: both will be competing on the card. On that night, Antonio McKee will end a five-year retirement to face William Sriyapai, while A.J. kicks off his tournament run against Georgi Karakhanyan.

It is not unprecedented for a father and son to compete on the same major MMA card. In fact, Haim and Aviv Gozali did it just last year at Bellator 209. But it is believed that if Antonio and A.J. emerge victorious, they would be the first to win bouts on the same major event.

While 24-year-old A.J. has plenty of motivation to fight — the featherweight Grand Prix comes with $1 million for the victor, along with the Bellator title — Antonio is 49, making his return something of a surprise, at least to followers of the sport.

“It’s been years in the making,” A.J. McKee told MMA Fighting. “I feel like it was inevitable, but he was waiting for the right time. He may be almost 50, but he still trains with us every day and he’s still grinding, still setting trends.”

For Antonio, this isn’t necessarily a one-off, bucket-list item. He’ll start with Sriyapai but says he’s ready to ride the momentum wherever it takes him.

Antonio acknowledges that his speed has waned a bit, but insists he is in great physical shape, and that his past ability to avoid damage has him not far off his prime. He’s so confident, he’s willing to face the very best in the division.

“I want a shot at the (lightweight) belt,” he said. “Who’s going to stop me? [Bellator champion Patricio] ‘Pitbull’? I’ll beat ‘Pitbull’ up, and my son would definitely kick his ass. With the level of wrestling I’m at, with the knowledge and position I have, the only question is whether my body can hold up. But nobody at 155 pounds can handle me. I’ve trained with [UFC lightweight champion] Khabib Nurmagomedov. He couldn’t pull his stuff off on me. I was 50 and out of shape, but I can still hang. I don’t see any major threats in this division.”

This prospect of a middle-age man challenging the current champion sounds preposterous on its face. But then again, when he reminds you he regularly trains with the likes of his son, Joey Davis and Aaron Pico, that is it’s own kind of irrefutable statement. Even if training isn’t exactly the same as fighting, it’s close. It’s a bellwether.

“He holds his own for sure,” A.J. said. “He’s been in there for years; he knows what he’s doing. He knows where people are going before they move. He has a feeling, a calm, that comes with age and wisdom. And that McKee grip? I don’t think anyone’s felt anything like that grip. I’ve seen him shake hands with people and bring them to their knees. It doesn’t make sense. Good luck breaking free from that.”

There’s also his past. Antonio McKee was no run-of-the-mill fighter. Even though he never reached worldwide renown, from August 2003 to September 2010, he didn’t lose a single fight, reeling off a 15-fight unbeaten streak that landed him in the UFC. There, he lost a close and disputed split-decision against Jacob Volkmann and was surprisingly cut immediately afterward. Still, he finished the first phase of his career with a record of 29-6 with two draws.

Despite his success, he was often criticized for a wrestling-heavy approach that both stifled the action and minimized the possibility of damage.

In an ironic twist, the fighters he’s developed have mostly earned reputations for being exciting in the cage, and McKee hints you may see some of that in him this time around.

“I’ve said for a while now I didn’t feel like I was complete,” he said. “I didn’t feel like I left the right taste in people’s mouths. Being older and more mature as a coach, father and friend, I see it different than I did when I was competing on the regular. I have more respect for the fans and for the promotion. I think back then, my maturity level didn’t match my skill level.”

On the card, Antonio will walk out first, fighting on the prelims. A couple hours before he fights, A.J. will walk out alongside his dad and corner him in that match before preparing for his own.

“I think it’s legendary, it’s iconic, it’s history-making,” A.J. said. “I still think he’s ahead of his time and I’m ahead of my time. It’s going to get to a point where people can no longer deny the McKee name in the fight world. My dad was undefeated eight years and no one knew who he was. I’m 14-0 and I’m still called a ‘prospect.’ I think we’re both underrated. But I think by the end of this tournament, people will know what the McKee name stands for, and it’s not just wrestling. It’s a lot of ass-kicking and knockouts.”

It’s fitting the McKees go into this million-dollar tournament as a unit. Antonio suffered through a difficult youth and was a victim of molestation by a family friend. In his teenage years, he was forced to navigate the drug dealers and gangs that populated his neighborhood. For most of his fight career, he made little money, a fact he says that led to his conservative style. He saw no reason to risk his safety for a payday of a few hundred dollars.

A.J. had his own hardships. From difficulties with school as a youth, to living in a house with five friends to cut costs, to sleeping on couches during the early days of his fight career, struggles threatened to sidetrack him. But his focus held strong.

Now, A.J. McKee is one of the favorites to win the tournament, and his father is by his side with a guiding hand. Should he capture the belt, A.J. says his days at featherweight are numbered. He plans to win the tournament and the belt, and then move up to lightweight. Somewhere along the way, he hopes to face ‘Pitbull’ and prove beyond a shadow of a doubt who is the best lighter weight fighter in Bellator.

“I see ‘Pitbull’ calling out Khabib and all this other s—t,” he said. “I think this man wants to fight everyone besides me. You’re searching other organizations, calling out other undefeated fighters and you have one in your own organization? Dawg, you sound like you’re just running scared to me. I can’t wait to get my hands on that belt. His time is coming.”

First, he’ll have to get past Karakhanyan, but that will only be part of the perfect evening the McKees are planning in Inglewood, Calif. A father-son double victory party only 30 miles from their home base? Doesn’t that sound amazing?

“People think I’m crazy and that I have nothing to prove, but this is me,” Antonio McKee said. “But being able to fight and to win on the same platform as my son, it’s never been done at this level. That alone is something that is going to go down in the history books, and I’m going to get in those history books one way or the other.”