LAS VEGAS – Ismael Barroso has mostly lost when he fought credible contenders.

Uzbekistan’s Batyr Akhmedov, who will fight on Barroso’s undercard Saturday night, knocked him out in the ninth round the last time Barroso boxed a top 140-pound opponent. The Venezuelan veteran is 40 years old as well.

Those are among the reasons Rolando “Rolly” Romero is a 10-1 favorite to beat Barroso on Saturday night, according to most sportsbooks. Romero realized in studying Barroso, though, that the experienced southpaw could become dangerous at times in their 12-round fight for the vacant WBA super lightweight title.

“He can crack,” Romero told BoxingScene.com. “That’s no joke. He can crack. Like he’s one of those dudes that you just don’t wanna get hit by. He can crack. He throws like these short [punches] out of nowhere. He’ll throw hella wide open and then, out of nowhere, just one short one. He’s a lot more tricky than people think. And on top of that, he’s got experience.”

Barroso (24-3-2, 22 KOs), who resides in Miami, has almost twice as many professional fights on his record as Romero (14-1, 12 KOs). Romero had only 35 amateur bouts, which makes the North Las Vegas native feel like he is always learning on the job.

“Everybody in boxing has more experience than me,” Romero said. “There’s nobody who don’t have more experience than me.”

The 28-year-old Romero will make his debut at the 140-pound limit when he battles Barroso for the WBA’s unclaimed 140-pound crown. Showtime will air Romero-Barroso as the main event of a tripleheader from The Cosmopolitan of Las Vegas (9 p.m. EDT; 6 p.m. PDT).

Romero was supposed to challenge unbeaten Alberto Puello for the WBA super lightweight title. Barroso, the WBA’s mandatory challenger in the 140-pound division, replaced Puello as Romero’s opponent last month because Puello failed a performance-enhancing drug test.

The Dominican Republic’s Puello (21-0, 10 KOs) tested positive for clomiphene, which typically is prescribed to women with fertility issues. Puello has been rendered champion in recess by the WBA, which is expected to strip Puello of his title if his B sample comes back positive.

Puello has a hearing regarding his temporary suspension scheduled for Wednesday with the Nevada State Athletic Commission.

Romero ripped Puello for using a banned substance (https://www.boxingscene.com/rolly-romero-on-puellos-ped-test-failure-lot-these-motherf-on-sht--174503). The former WBA interim lightweight champion is fully focused now, however, on his new opponent in what will be his first fight since Gervonta Davis (29-0, 27 KOs) knocked him out in the sixth round of their Showtime Pay-Per-View main event last May 28 at Barclays Center in Brooklyn.

“Any fight where there’s two punchers,” Romero said, “is gonna be a great fight.”

Showtime is set to televise a 10-round co-feature in which Cuban junior welterweight contender Rances Barthelemy (29-2-1, 15 KOs, 1 NC) will oppose Omar Juarez (14-1, 5 KOs), of Brownsville, Texas, before Romero faces Barroso. Akhmedov (9-2, 8 KOs) will face Chicago’s Kenneth Sims Jr. (19-2-1, 7 KOs) in the opener of Showtime’s telecast, a 12-round WBA super lightweight eliminator.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.