For Oscar Valdez, Friday’s fight card at Tucson Arena is about returning home with a belt in hand, and having no plans to give it up.

For the sport of boxing, it’s potentially much more than that.

Valdez is one of four undefeated fighters on the two main events Friday, defending his WBO featherweight title against Filipino Genesis Servania, in a loaded card. Top Rank is forwarding the broadcast to ESPN for the purpose of attracting eyeballs to an endangered sport that has long been partially hidden on premium or pay-per-view platforms.

“I know a lot of people don’t know where it is,” Top Rank president Todd DuBoef said of boxing. “It’s, ‘I haven’t seen a fight for a while. Where is it on?’ But they know where UFC is because it’s on FS1.”

This one is on ESPN. Regular, ubiquitous, and almost free ESPN.

It will be the first official ESPN show since Top Rank signed a minimum four-year deal with the gigantic sports network last month, though Top Rank already promoted three shows on ESPN earlier this summer, with Manny Pacquiao, Vasyl Lomachenko and Terence Crawford headlining each.

Together, DuBoef said, those three ESPN cards averaged about 1.5 million viewers each — about 60 percent more viewers than UA football attracted last week on ESPN when the Wildcats played at UTEP — and that was only in the United States.

Tonight’s fight card will also be shown in 150 countries around the world, potentially multiplying the U.S. audience by a factor of three, four or many more times.

The international viewing audience could spike because of the eight countries the fighters represent. Valdez is one of six Mexican fighters on the card, while others are from Australia, Nicaragua, Uzbekistan and Brazil.

Then there’s Michael Conlan of Belfast, Northern Ireland, a close friend of Conor McGregor who became an international celebrity after losing a controversial Olympic fight to a Russian in Rio last year.

After that fight, Conlan threw middle fingers at the judges and later sent a tweet to Russian president Valdimir Putin, asking “How much did they charge you bro??”

Asked about that incident before Wednesday’s Tucson Arena press conference, the impeccably dressed and well-spoken Conlan smiled about the support he received afterward, in Ireland and elsewhere.

“They loved it all over the world,” Conlan said. “My Twitter followers went from about 30,000 to about 105,000.

“The Americans loved (the Putin tweet). He didn’t respond but it was bit of off-the-cusp stuff. It was all fun and games.”

The domestic audience, meanwhile, could get a boost from a direct lead-in after a Cubs-Brewers baseball game that has playoff implications, and a 7:30 p.m. starting time that is prime time in the West and maybe not too late for sports buffs in the East.

That’s the kind of slot DuBoef wants.

“It’s where the sport should be,” he said. “It’s been jumping around. It’s been on premium channels for a while but we think sports fans are watching college football and baseball and the NFL — and if we can put in boxing in where it will be sandwiched between them, we believe it will have a bigger platform for growing the audience here.”

The card’s domestic and cross-border appeal starts with Valdez, a native of Nogales, Sonora, who spent elementary school in Tucson and now splits his time between Los Angeles and Hermosillo, Sonora.

Valdez first appeared in Tucson on a Dec. 2015 card, stopping Ernie Sanchez in the third round in a show that also featured Phoenix welterweight Jose Benevidez.

This time, Valdez is returning with a WBO title he won in July 2016 and has since defended twice. And this time, while Valdez’ first Tucson fight came before about 3,000 people and a UniMas television audience, there will be a bigger expected crowd and some ESPN magnification.

“The last time I fought here I said I was going to bring the title back, so I’m very excited,” Valdez said. “Once I got the news (it would be on ESPN) I was very motivated, very excited because I’ll get a lot of exposure. A lot of people are going to be able to see me for free now. It’s a chance for the people to see who Oscar Valdez is.”

While Valdez will take on the undefeated Servania in the main event, the co-main also features some cross-border appeal: Hart brings his tough-talking Philly cred against the soft-spoken confidence of Ramirez, the Sinaloan super middleweight known as “Zurdo” (or “Lefty”).

“He has been talking and talking a lot but I don’t like to talk too much,” Ramirez said. “I let my fists do the talking in the ring.”

The women’s bout on the card also has domestic appeal. Not only did Mikaela Mayer fight for the USA in the Rio Olympics, but she preceded that with a “one of a kind” Dr. Pepper commercial, where she discussed her background in boxing and modeling.

“Millions of girls are told they’re pretty,” Mayer said in the commercial, as she prepared to train. “But not many end up becoming a model. Even fewer decide to put their face in front of someone who wants to rearrange it. And now, instead of fighting for a cover shot, I’m fighting for gold.”

Mayer missed out on that gold medal — and the bronze — when she also lost a close Olympic quarterfinal bout. Two judges scored it 39-37 in favor of Russian Anastasiia Beliakova while another called it a draw.

Mayer’s manager, George Ruiz, said this week that “a lot of fighters who fought Russians that day did not get the decision. … Mick Conlan was the most famous of them.”

But as did Conlan, Mayer moved on. Her fight Friday against Allison Martinez of Spring, Texas, will be her second as a pro, after she stopped Widnelly Figueroa early in the second round last month in Los Angeles.

“That was something really hard to get past but everything kind of falls into place for a reason and I’m really happy about where I am now,” Mayer said. “Maybe if I would have won gold, maybe I would have gone for another Olympics. Maybe I wouldn’t reach out and see what my options were in turning pro. I’m glad I’m where I am.”

Mayer isn’t scheduled to be on the ESPN portion of the card, since her fight with Martinez is scheduled for the undercard that begins at 4:30 p.m., and will only be televised via the WatchESPN app.

But ESPN will carry Valdez-Servania, Ramirez-Hart and Conlan’s fight against Kenny Guzman of Montana, a trio of featured bouts that Top Rank promoter Bob Arum is gushing over, even by his normally outspoken standards.

“I am so excited for this card,” Arum said. “I think this card will demonstrate, as did the Lomachenko fight and the Crawford fight, what boxing has to offer. With the help of ESPN we are going to make this sport back to where it was when I first started. It was one of the leading sports in the world.”

Sportswriter for the Arizona Daily Star covering Arizona Wildcats basketball