Edwin De Los Santos takes exception to carrying the replacement opponent label heading into this weekend.

The description is technically true, as the Dominican southpaw was tabbed to replace an unavailable Jezreel Corrales against unbeaten lightweight Jose Valenzuela this Sunday at Crypto.com Arena in Los Angeles. Corrales was unable to secure a travel visa in time to make the trip from Panama, with the development along with confirmation of De Los Santos as the new opponent revealed to the public Wednesday afternoon.

“I don’t consider myself a substitute because I’ve been training for this fight for two months,” De Los Santos said of the opportunity. “I knew there was a real possibility I was going to be in this fight.”

Event handlers were equally prepared for the moment as well, informing De Los Santos’ team—including world-class promoter Sampson Lewkowicz—in early August that the 22-year-old was officially on standby for the fight.

The hope all along was for Corrales (26-4, 10KOs) to have his travel issues sorted out in time to challenge the 23-year-old Valenzuela (12-0, 8KOs), a red-hot lightweight rapidly transforming from prospect to contender. Corrales is a former WBA junior lightweight titleholder with enough tricks left in his arsenal to have presented a far stiffer test than when Valenzuela tore through faded former WBC 130-pound titlist Francisco Vargas inside of a round in April.

The glass half-full view of the opponent switch is the suggestion of a more fan-friendly style matchup against a fresher and more aggressive southpaw.

De Los Santos (14-1, 13KOs) is a noted puncher, though dealt a harsh learning lesson in an eight-round loss to William Foster III in their Showtime-televised matchup of unbeaten prospects on January 7 in Orlando, Florida. He quickly rebounded, blasting out unbeaten Luis Acosta in the second round of a fight that also aired on Showtime’s ShoBox series on March 11 in Deadwood, South Dakota.

The plan was always for De Los Santos to fight in September, though originally targeting a lower-profile opportunity. The worst-case scenario was appearing on the non-televised undercard of a September 9 Showtime card in Atlantic City.

The best-case scenario is precisely where he is this weekend.

“I was already in the gym, prepared to fight next week on September 9,” noted De Los Santos, who fights for the third time this year. “I’m the real challenge and I will knock Valenzuela out. I’m a different fighter. I learned from my loss and I’m going to make sure it never happens again.”

Valenzuela-De Los Santos opens a four-fight Fox Sports Pay-Per-View (Sunday, 9:00 p.m. ET, $74.95). Headlining the show, former unified heavyweight titlist Andy Ruiz (34-2, 22KOs) faces two-time title challenger Luis Ortiz (33-2, 28KOs; 2NC) in a scheduled 12-round WBC semifinal title eliminator

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox