It’s no easy task.

Jermell Charlo is a three-belt champ at 154 pounds who’s beaten every man he’s ever faced in a boxing ring, including an 11th-round rematch stoppage of the only man who’d ever beaten him.

He’s ranked first in the weight class by Ring magazine, Boxrec.com and every other worthwhile list-making entity, and seems especially motivated to put on a show in a Saturday night main event.

But Brian Castano seems unfazed.

At least on the surface.

“Charlo is a great fighter,” he said at a recent media conference. “There’s no doubt about it. 

“But I came here to do my job and I’m going to come forward. I’m the type of fighter that is always going after you. My goal has always been to go up against the best of the best and the elite of my division. 

“I have that chance now, and I’m going to prove why I deserve this chance.”

The chance comes at the AT&T Center in San Antonio, where he and the lighter, younger Charlo brother meet atop a Showtime card in a scheduled 12-rounder that’ll crown the division’s first four-belt king.

The three-bout show begins at 9 p.m. ET.

“I will leave my heart in the ring and do everything in my power to become the undisputed, unified champion of the world,” Castano said. “I think that Charlo is in the prime of his career as well. 

“That’s why I looked for this fight. This is the fight I’ve been looking for because we are both in the best moment of our career, and I want to take advantage of it.”

Indeed, though the Argentine has been a pro for nearly nine years, the 31-year-old Castano’s path toward a Charlo fight essentially began five months ago in Southern California – where he routed Patrick Teixeira over 12 rounds to win the Brazilian’s WBO share of the 154-pound championship.

The win instantly linked him with countrymen Carlos Monzon, Sergio Martinez and Victor Galindez, and Castano said a win would challenge the national soccer team’s hold on Argentina’s sports fans.

“If I win, the glory would be equal to a potential Argentina World Cup title next year,” he said. “However, soccer is different because you have ten other people that you can rely on. 

“Boxing is more of an individual challenge. (Lionel) Messi has 10 teammates that he can pass the ball to when things get tough, but I’m on my own when I’m in the ring.

“This opportunity to make history for my country and Latin American people brings out powerful emotions in me. I don’t want to let down my Latin American people from all over the world. I feel an immense amount of pride in that, and I am up to the challenge.”

Castano worked the low-profile side of the street through his formative years before a split-decision win over once-beaten Michel Soro on the Frenchman’s home turf in 2017. 

He fought to a split 12-round draw against long-time 154-pound claimant Erislandy Lara in Brooklyn in 2019, then parlayed the deadlock into the Teixeira two fights later. 

A five-round defeat of Wale Omotoso came between the Lara and Teixeira outings and was broadcast by Fox, where ex-lightweight champ Ray Mancini got a first-hand look as Castano’s rough-hewn skill set.

And “Boom Boom’s” message for those thinking Castano has no chance?

“He does,” Mancini told Boxing Scene. “He’s a good puncher with deceptive hand speed and a pretty tight defense. I think Charlo wins because of his experience in big fights, but it’ll be a war.”

Charlo is listed as a minus-250 favorite by DraftKings, which means it’ll take a $250 investment to return a $100 profit if he wins. Castano, meanwhile, is a plus-180 proposition, which means a $100 wager will pay off an additional $180 if he pulls off the upset.

Charlo’s lone loss came on a unanimous decision against Tony Harrison 31 months in Brooklyn, but he regained his WBC belt with a stoppage of Harrison a year later in California. He added IBF and WBA straps with an eighth-round KO of Jeison Rosario in his most recent fight last September in Connecticut.

Still, according to Randy Gordon, it’ll take a fighter of Castano’s prowess to extend the favorite.

“I think Castano will bring out the very best in Charlo,” he told Boxing Scene. 

“Charlo is a complete fighter and continues to get even better. His jab is pulverizing, and his combinations are lethal. I am not sure there is any 154-pounder who can beat him.”

* * * * * * * * * *

This week’s title-fight schedule: 

SATURDAY

IBF/WBA/WBC/WBO junior middleweight/super welterweight titles – San Antonio, Texas

Jermell Charlo (IBF, WBA, WBC champ/No. 1 IWBR) vs. Brian Castano (WBO champ/No. 3 IWBR)

Charlo (34-1, 18 KO): Second WBC title defense; KOs in four of five career title-fight wins

Castano (17-0-1, 12 KO): First title defense; Eighth fight in the United States (6-0-1, 3 KO)

Fitzbitz says: I won’t lie. I wanted to believe Castano would pull off the surprise, but the more I look at him the more I think Castano’s a guy who’s going to make the twin look good. Charlo in 8. (85/15) 

This week’s trash title-fight schedule

WBA “world” cruiserweight title – Brussels, Belgium

Ryad Merhy (champion/No. 13 IWBR) vs. Zhaoxin Zhang (No. 14 WBA/Unranked IWBR)

Why it’s trash: The trash label applicably applies to a percentage of WBA title fights regardless of the principals involved. But here, it’s the usual. There’s a guy above Merhy in the rankings. And, P.S., the challenger has never beaten anything close to a world-class foe. But sure, award a belt. Why not? 

Last week's picks: None 

2021 picks record: 26-7 (78.7 percent) 

Overall picks record: 1,182-382 (75.5 percent) 

NOTE: Fights previewed are only those involving a sanctioning body's full-fledged title-holder – no interim, diamond, silver, etc. Fights for WBA "world championships" are only included if no "super champion" exists in the weight class. 

Lyle Fitzsimmons has covered professional boxing since 1995 and written a weekly column for Boxing Scene since 2008. He is a full voting member of the Boxing Writers Association of America. Reach him at fitzbitz@msn.com or follow him on Twitter – @fitzbitz.