He’s a Star for the Digital Age. Some Think His Belt Is Paper.

LAS VEGAS — In early May, a month before a scheduled fight for the undisputed lightweight championship in Melbourne, Australia, Devin Haney stood mid-ring at the Top Rank Gym here, trading punches and trash talk with a contender named Kenneth Sims.

Haney, the World Boxing Council lightweight champion, thumped Sims’s midsection. One of Sims’s counter punches landed on Haney’s beltline.

“Keep ’em up, Kenny,” Bill Haney, Devin’s father and head trainer, shouted from outside the ropes.

“Wasn’t none of ’em low, Bill,” Sims replied during a brief pause between punches.

Five years ago, Haney, now 23, might have recorded much of this session — 10 total rounds against three partners — and uploaded footage to YouTube. Exposing viewers to normally private high-level sparring earned Haney a following, even as a teenage up-and-coming pro. And keeping pace with bigger-name fighters caught the attention of powerful promoters. A video of a teenage Haney sparring with Shakur Stevenson in 2015, now a super-featherweight world champion, has collected 1.6 million views.

But this session is exclusive, at Haney’s insistence. No phones, no cameras and no observers besides sparring partners and coaches.

The new secrecy befits the stakes for his fight against George Kambosos Jr. Organizers expect 50,000 spectators at Marvel Stadium for a main event that starts around 11 p.m. Eastern time Saturday and early Sunday afternoon local time.

Kambosos (20-0-0, 10 knockouts), a rugged Australian, holds titles from three major sanctioning bodies. For Haney (27-0-0, 15 knockouts), a win would earn him the undisputed lightweight championship and vindicate his unorthodox career choices.

He turned professional at 17, fighting in Mexico because few states would issue a fighter that young a license. At 19, Haney established his own promotional company, partnering with major promoters for his bouts. Haney will face Kambosos under a short-term deal with Top Rank.

And while flooding YouTube with footage helped grow his audience, Haney said monetizing that following means treating his boxing career like a media business.

“I’m at the point in my career where I want everyone to watch the fight,” Haney said. “I want to save the footage and the eyeballs for one night, to be sharp and be 100 percent.”

Later in the session, Sims landed a straight right to Haney’s forehead.

Haney shrugged at him.

“You can’t hit,” Haney said, adding an expletive.

“Think you can?” Sims said.

“Better than you.”

That kind of verbal back-and-forth has always helped sell fights, especially at pre-fight weigh-ins, but platforms like YouTube and Instagram have also helped boxers of various skill levels bolster their popularity and paydays. Jake Paul, best known as a YouTube personality, has parlayed his fame into a lucrative boxing career, pummeling a string of aging non-boxers.

But Haney is not a YouTube influencer who boxes. He is a world-class boxer who is also internet-savvy, part of a generation that employs social media as deftly as they do their first language. Haney has 1.2 million Instagram followers, and, like the rising lightweight star Ryan Garcia, he has an intuitive feel for using social platforms to meet his business goals.

Garcia, who has 8.8 million Instagram followers, and a rivalry with Haney dating back to their days as teenage amateurs, is signed with Golden Boy Promotions. He does not have a world title, but he co-stars with Portland Trail Blazers guard Damian Lillard in a Gatorade commercial.

Haney, for his part, uses his company, and short-term deals with industry titans, to secure the matchups he wants. Between 2019 and 2021, Haney partnered with Matchroom Boxing for six bouts, which aired on the sports streaming service DAZN. The Kambosos bout will air on ESPN under its agreement with Top Rank.

Bill Haney, who once owned a recording company, compares his son to an independent artist working with major labels on his own terms.

“We came to Top Rank with a fan base, with an infrastructure,” Bill Haney said. “The only thing we needed was distribution. That’s ESPN.”

Still, the perception persists among some of his contemporaries that Devin Haney, whose Instagram feed features training footage sprinkled with photos of his luxury cars, is a social media influencer masquerading as a world champion.

After winning the W.B.C. interim title in September 2019, Haney was promoted to “regular” lightweight champion without a title fight. Because he gained his title in a boardroom, some boxers view him as a paper champion for the digital age.

“He’s an email champ,” Gervonta Davis, who holds a World Boxing Association title at lightweight, said on Showtime Boxing’s podcast. “He’s fighting because somebody mailed him the belt.”

Haney, whose title defenses include a win over the former world champion Jorge Linares, argues that he’s a legitimate champion. Linares stunned Haney with a right hand late in that bout, and afterward Haney peppered the veteran with questions about how he could improve.

“I think I’m the best, but I know that I will get better,” Haney said. “I’m still learning on the job, and I understand that.”

The Haneys attribute that willingness to learn from almost anyone to their start in the sport. Bill Haney is Devin’s head trainer, but he had never boxed or coached. He owned a hip-hop record label in Oakland, Calif., before selling it and moving to Las Vegas. When Devin began boxing as a grade-schooler, Bill immersed himself in the sport, learning from Devin’s trainers and eventually opening his own gym.

Bill Haney likens their current setup to a football team: He is the head coach, working with a rotating cast of high-level trainers as coordinators on a fight-by-fight basis, each adding to the Haney playbook.

“If I tell him, ‘come back with the hook,’ that’s Eddie Mustafa Muhammad,” Bill Haney said, referring to the veteran trainer and former light heavyweight champion. “If I say, ‘close it up and walk down,’ that’s Floyd Mayweather Sr. If I say, ‘get out of neutral,’ that’s Roy Jones Jr. Those are the plays that we learned from the greats.”

Bill will work Devin’s corner against Kambosos, but almost missed the opportunity. His visa to enter Australia was only approved on Friday morning, the delay stemming from a drug possession conviction in the early 1990s. According to a Top Rank spokesperson, Bill boarded a flight on Friday in Los Angeles, and was scheduled to arrive in Melbourne at 9 p.m. Saturday local time, just 14 hours before the opening bell.

Likewise, the English trainer Ben Davison, who was scheduled to assist Haney for the Kambosos fight, has been denied a visa. Davison is a past associate of Daniel Kinahan, the boxing power broker accused of leading an Irish organized crime group.

The last-minute coaching changes further complicate a difficult task. Kambosos won titles from three sanctioning bodies by upsetting Teófimo López last November, overwhelming Lopez with a late surge. He achieved his highest output (88 punches) and most connections (26 punches) in the final round of that title bout.

Kambosos, 28, shares Davis’s skepticism for Haney’s W.B.C. title.

“This guy acts like a gangster. He ain’t a gangster,” Kambosos said at a pre-fight news conference. “He’s as fake as that belt.”

Beyond Saturday’s bout lie high-profile possibilities. If Haney wins, Kambosos has the contractual right to a rematch in Australia later this year. Haney has also jousted verbally with Davis, with whom he shared a contentious sparring session in Las Vegas, and who boosted his cachet by flattening Rolando Romero with a roundhouse left at a sold-out Barclays Center last Saturday.

Garcia is also lobbying for a Davis bout, and any of those fighters could also potentially match up with Vasiliy Lomachenko, the former champion from Ukraine who canceled a planned bout with Kambosos when Russia invaded his native country.

But Haney recognizes that earning a top seed in that informal tournament, and gaining in-ring credentials to match his online following, depends on defeating Kambosos.

“This is the Super Bowl of the lightweight division,” Haney said. “How can I look past it when it’s for everything?”