It’s not uncommon for fighters to have multiple trainers throughout their careers. Xander Zayas has had the same one since he was 11.

Fast forward 12 years, and Javiel Centeno remains by his side as they prepare for the toughest and most important test of their careers.

Zayas (22-0, 13 KOs) is scheduled to face Abass Baraou in a 154-pound title-unification bout on Jan. 31 at Coliseo de Puerto Rico in his hometown San Juan. A victory on their island would mean even more.

“Javiel Centeno is like a second dad to me,” Zayas told The Ring. “He’s somebody who inspired me inside and outside the boxing world. Great man, great family guy and somebody who pushed me to my limit. He’s somebody who understands me and knows me and knows what we need to work on [and] where we can push. He knows me in every way, shape, or form.”

Zayas, 23, could become the first Puerto Rican to unify a title on the island and the youngest one in boxing. Ivan Calderon and Mexico's Giovani Segura met in the only other unification clash to take place there, with the latter scoring an eighth-round KO against the home fighter in 2010.

“It's special the fact that this could happen in Puerto Rico,” Centeno told The Ring. “First of all, it's one of his dreams, and his dreams are our dreams. We always tell him that as a team, we want the best for him and we follow his dreams, right? We want to make his dreams happen. So it's like giving a kid a gift on Christmas that they want, and you're able to provide that. I want to feel that. We did it once, and I want to feel it again.”

Zayas enters the unification bout with the WBO title, while Baraou, 31, is the WBA champion. The bout is available on Top Rank Classics through The Roku Channel, Tubi or Vizio. Through mobile or desktop, the entire card can be seen on trboxing.co/TopRankClassics.

Zayas and Centeno first crossed paths at an amateur tournament in South Florida. Zayas, who moved to the U.S., was supposed to fight Eric Tudor, coached by Centeno. The bout, however, didn’t happen.

Zayas’ previous trainer, Peter Balcunas, passed away not long after that tournament. In need of a new mentor, the impression Centeno left led Zayas back to him.

“Xander has that personality that you meet him once, and you feel like you've known him forever,” Centeno said. “We clicked right away. He picked up everything that I was teaching very quickly.”

Centeno refined a scrappy and aggressive Zayas, who was always eager to be the first to do whatever the team was working on. Even as one of the smallest kids in the gym, Zayas wasn't backing down from anyone.

Zayas dialed back the aggressiveness and added other facets to his game, particularly improving his jab, under Centeno's tutelage. As he matured, Zayas became one of the best amateurs in the U.S.

“We did that for a while and started to change his game a little bit. Then he started to grow into his jab, so he didn't have to be as aggressive as he was,” Centeno said. “All of a sudden, he started winning competition after competition and tournament after tournament, and got on the national team. And he stuck with that style of boxing, as opposed to just being on the inside. He wanted to box, and he was willing to learn.”

Although Zayas has plenty of success, it was after a setback that Centeno saw how far he could go.

At 14, Zayas lost in the Silver Gloves in Washington, D.C. Everyone on his team team believed he was robbed. Rather than complain about his misfortune, he asked Centeno why he lost the fight.

“He really wanted to understand why the judges thought the other guy won,” Centeno said. “So we sat down and talked, and I was like, 'This is a 14-year-old who's asking questions that sometimes 18, 19, 20 year olds don't ask.' We sat down, and we talked and I explained the situation. There might have been things like this that the judges saw, and they swayed in his direction. He's like, ‘OK, that's something we can work on.’”

Zayas hasn’t lost a fight since.

In 2019, he signed with Top Rank at 16, making him the youngest fighter it has ever signed. Seven months later, he made his pro debut.

It has largely been a streamlined path for Zayas to this point. He became the youngest champion in boxing at the time when he defeated Jorge Garcia by unanimous decision to win the then-vacant WBO title on July 26.

Zayas’ triumph also made him the first fighter Centeno had guided from childhood to a world championship.

“I've seen everything that he's gone through to get to this point, whereas sometimes you get fighters who are at a certain level, and then you can take them to a title," Centeno said. "It's a little bit different because you didn't see everything else that was going on. You've only had a short period of time with them. With Xander, I've seen him grow in style, maturity and just in his general demeanor. He's just grown up in front of me, so it's different. … He’s my baby.”

And if Zayas can emerge victorious against Baraou, it’ll be another memory he can reminisce over with Centeno, who has become so much more than a trainer.

“He makes it really special,” Zayas said. “Just having a close circle type group, where everybody is very personal and intimate in the sense that we're family, it's so much more than just boxing or being able to accomplish all those things with those people.

"It's amazing because when we sit down in 20 years, we're going to look back at it and say, ‘Hey, we made it happen from the ground up.’”