'Flash' is the betting favourite ahead of their Las Vegas mega-showdown, but plenty of fighters have thrown their hat into the ring behind the incumbent champion to prevail.

But while Conor Benn and Tim Bradley feel Barrios will keep his crown, Claressa Shields has backed Garcia to leave Nevada with a new achievement on his career record.

The undisputed heavyweight champion is part of a busy weekend that includes her own rematch against Franchon Crews-Dezurn, live on DAZN from Detroit.

• BUY NOW: Barrios vs. Garcia PPV for $69.99 / £24.99 or via DAZN Ultimate Tier to get PPVs included in your subscription 

Asked who she expected to prevail in Sin City however, and Shields admitted she sees success to likely follow, suggesting that Barrios does not have the extra gear to find.

"I don't like Ryan Garcia at all, but I will say that I think that he will become champion against Mario Barrios," she told DAZN News.

"That's not a knock to Mario Barrios. It seems like when it gets time for Mario Barrios to go that extra mile, he doesn't do it.

"He's a great fighter. He has great skill, great fundamentals, but he doesn't use them. It's like he fights to be in a tie.

"It's like his fights are almost like watching a sparring match of two guys going 70 or 80 percent."

Shields pointed to Barrios' recent record, including a draw with an aging Manny Pacquiao, as further proof that Garcia may bring more ideas to the table on Saturday.

"Pacquiao is great, but [there is] no way that old guy should have been able to get in there and do anything with Mario Bardos," she added.

"He had a draw against him. Now we have Ryan Garcia, who is way more athletic.

"He got that hook. He's skilled himself, and he knows that this is a fight that all he has to do is just keep pressing and pressing and throwing quick punches. 

"I don't know if Mario Barrios is going to push past his limits to where he can actually win a fight.

"I think that this is a perfect opportunity for Ryan to become a world champion after these fights and all these attempts.

"Good for Ryan if he can win. They're both probably evenly matched as fighters. But I just feel like Mario Barrios is just too laid back as a fighter.

"He doesn't know how to win rounds dominantly. It's like if the fight is kind of close, he wants to keep it close. You have to dominate.

"I think that Ryan knows how to do that, and he's really fast. And I don't know if Mario is going to be able to see that fast hook from Ryan."

3 fight nights, 1 unmissable weekend - only on DAZN

Watch three amazing fights this weekend - Feb 21-22 - exclusively on DAZN. It's Barrios vs. Garcia for the WBC welterweight title on PPV; with Wood vs. Warrington II, and Shields vs. Crews-Dezurn II on DAZN subscription. Get all three all included with DAZN Ultimate Tier. 

For more information, pricing and to watch, click here.