LAS VEGAS — In the week leading into his first fight in more than a year, the U.F.C. star Conor McGregor has exuded a confidence familiar to anyone who has followed his transformation from Ultimate Fighting Championship contender to the fight promotion’s biggest star.
His posture, perfect. His suits, tailored. His chin, held high.
But his trademark trash talk has been absent. Instead, McGregor saluted fans and shook hands at a midweek news conference with the rugged veteran Donald Cerrone, his opponent in the main event at U.F.C. 246 on Saturday night. Over the next half-hour he complimented Cerrone, who is nicknamed Cowboy, on everything from his fighting acumen to his reptile-skin blazer (made of python, Cerrone said).
The new sales pitch for McGregor and the U.F.C.: Conor the sportsman, not Conor the heel.
The version of McGregor on display ahead of his first bout since a loss to Khabib Nurmagomedov in October 2018 is friendlier but more focused than before, and bent on redemption from high-profile losses and image-tarnishing arrests.
No matter which side he shows, McGregor is undoubtedly a critical part of the U.F.C.’s plans for 2020 as a star who has attracted fight fans and mainstream audiences. McGregor figures to boost the promotion’s ticket and pay-per-view sales by simply entering the octagon to fight Cerrone, a fan favorite known for taking fights across divisions who is also coming off consecutive losses. An impressive win by McGregor, who already owns several U.F.C. sales records, would set him and the promotion up for still more paydays this year.
“Fully prepared, fully committed Conor McGregor — there’s no one that can touch me,” the 31-year-old fighter said during Wednesday’s news conference. “I made this game what it is. I’m going to go in there and remind everyone, and show the world Jan. 18.”
But McGregor has spent the last 15 months estranged from the sport he claims he built, dealing with a string of legal issues. The brawl that erupted after the loss to Nurmagomedov earned McGregor a six-month suspension and a $50,000 fine from Nevada regulators. McGregor also pleaded guilty in two assault cases, one for smashing a tourist’s phone in Miami, and another for slugging a 60-year-old bar patron in Ireland.
McGregor has avoided talking about two cases that are potentially more severe, separate police investigations in Ireland of sexual assault. The New York Times reported on Wednesday that he had not been charged, and the existence of the investigations does not imply that McGregor is guilty of any crime.
Through a publicist, McGregor has denied all accusations of sexual assault. The U.F.C. president, Dana White, said Wednesday that the investigations never jeopardized Saturday’s showdown.
McGregor was silent when asked about the cases, though he told ESPN in an interview broadcast Monday that things just needed to play out. “Time will reveal all, time will tell all,” he said. “And then that’s it.”
The fight card features no title bouts and depends mainly on McGregor to drive sales.
According to the Nevada Athletic Commission, McGregor’s loss to Nurmagomedov drew 17,835 spectators and $17.2 million in ticket revenue. Both figures are records for M.M.A. events in the state. Of the top six grossing M.M.A. cards in Nevada, McGregor has headlined five. His August 2017 boxing match against Floyd Mayweather earned $55.4 million in ticket revenue, according to the commission. McGregor is the only fighter to appear on the top-10 gate revenue lists for both boxing and M.M.A. events.
McGregor’s legal issues have not alienated his most dedicated fans. In fact, the U.F.C. incorporated several of McGregor’s arrests into prefight promotional videos, casting them as consequences of immature acts that McGregor has outgrown.
White and McGregor said this week that they hoped the fighter could compete three times this year, a schedule that depends in part on McGregor’s avoiding trouble. They teased a series of possibilities for the rest of 2020, including rematches with Mayweather or Nurmagomedov, a quick turnaround fight in March, or even a boxing match with Manny Pacquiao.
“Anything is possible,” White said. “Let’s see what happens on Saturday.”
Oddsmakers foresee a McGregor win, with many sports books seeing him as a 3-to-1 favorite over Cerrone.
Without McGregor, it is not clear which fighters on U.F.C.’s roster are capable of generating mainstream appeal.
Ideally, multiple athletes would fill that role, the way elite quarterbacks like Tom Brady, Aaron Rodgers and Russell Wilson all function as N.F.L. standard bearers. But while McGregor was inactive, the U.F.C. did not always have a single, standout, crossover star.
The former bantamweight champion Ronda Rousey played that role in the mid-2010s, but she has not fought since 2016, after back-to-back losses, and she has not publicly expressed interest in returning.
Her predecessor, the longtime welterweight champion Georges St-Pierre, took a four-year hiatus starting in 2013 and ending with a November 2017 win over Mike Bisping. Last year, St-Pierre, a Canadian, retired for good.
The light-heavyweight champion Jon Jones, who currently tops the U.F.C.’s pound-for-pound rankings, rode a string of spectacular wins to stardom in the early 2010s. But arrests and three failed tests for performance-enhancing drugs have sidelined him for long stretches, limiting his profile.
McGregor is unambiguously famous, however, and in a sport where pay is proportional to the size of the audience a fighter draws, a star at the top of the roster has other U.F.C. fighters envisioning their own paydays.
Jorge Masvidal, a welterweight contender who beat Nate Diaz in a November fight at Madison Square Garden that was attended by President Trump, is in line for a fight with the champion Kamaru Usman. But Masvidal told reporters on Thursday that he would rather fight McGregor, framing the choice as a business decision.
“If me and Conor go in the octagon, what happens? It’s one of the biggest fights in history,” Masvidal said. “Just by math, proven by what Conor’s been doing, the last couple fights that I’ve had — the engagement, the pay-per-views.”
He added, “It’s a formula for success.”
The first windfall goes to Cerrone, a 36-year-old fighter from New Mexico, who was chosen as an opponent because his fighting style when matched up against McGregor’s should produce a high-impact, high action bout.
At his best, McGregor dazzles opponents with speed, power and timing. In December 2015, he flattened the featherweight champ Jose Aldo with a single straight right hand, ending a heavily hyped title fight in just 13 seconds.
Cerrone, who has won 36 of 50 career bouts, is a versatile kickboxer who is willing to endure punishment before inflicting it. He has competed 33 times under the U.F.C. banner, which is tied for the record. But he has never headlined a pay-per-view event. Saturday represents a change to his career’s trajectory.
“Here’s the biggest one. Let’s see,” Cerrone said.
Where McGregor has fought just once since November 2016, Cerrone has competed 11 times over that span. It’s not clear, though, whether staying that active gives him an advantage. Cerrone has five wins and six losses in those fights, and was knocked out in his last two bouts.
Still, he enters Saturday with a size advantage. Both fighters were expected to weigh in below the contracted 171-pound limit, but Cerrone stands at 6 feet tall to McGregor’s 5-foot-9.
McGregor said he would neutralize Cerrone’s size with speed and strategy.
“I like him a lot. He’s a good guy,” McGregor said. “But I can read Donald like a children’s book.”