NEW YORK – The closer they get to their fight, the more Ivan Redkach senses Danny Garcia considers it simply a tune-up for bigger fights against southpaws Errol Spence Jr. and Manny Pacquiao.

Redkach previously believed Garcia viewed him as a dangerous opponent, despite the wide odds on their 12-round welterweight fight Saturday night at Barclays Center in Brooklyn. Not anymore.

“The biggest weakness I see in Danny is that he’s not taking this seriously,” Redkach said during of an open workout Wednesday. “He’s counting on this as a tune-up fight, and that’s a big mistake. This is not going to be a tune-up fight for him.”

Ukraine’s Redkach, 33, scored the biggest win of his career in his last bout, an upset of former IBF welterweight champ Devon Alexander in Redkach’s welterweight debut. Redkach (23-4-1, 18 KOs) dropped Alexander (27-6-1, 14 KOs) three times in the sixth round, the round in which he won by knockout June 1 in San Jacinto, California.

The 31-year-old Garcia (35-2, 21 KOs) hasn’t fought since knocking out Adrian Granados (20-8-2, 14 KOs, 1 NC) in the seventh round of their April 20 fight at Dignity Health Sports Park in Carson, California. He hopes defeating Redkach leads to a lucrative pay-per-view showdown with Spence (26-0, 21 KOs), the IBF/WBC welterweight champ, or Pacquiao (62-7-2, 39 KOs), who owns the WBA 147-pound title.

“Danny is already looking ahead to a fight with Errol Spence Jr. or Manny Pacquiao, but before he gets to them, he picked me,” Redkach said. “I know it’s because I’m a southpaw. But he’s going to get a rude [awakening] on fight night.

“This win will change my life and I’ve already worked my whole life to get to this moment. I want to win this fight and then the biggest fights at welterweight will be open to me. Right now, I’m only focused on my fight Saturday night.”

Philadelphia’s Garcia has lost only 12-round decisions to Keith Thurman and Shawn Porter, but Redkach predicted he’ll become the first fighter to stop the durable Garcia inside the distance.

“I’m going to knock him out,” Redkach said. “That’s how I see this fight going. We’re going to leave it all in the ring and I’m going to come out victorious.”

Showtime will air Garcia-Redkach as the main event of a tripleheader Saturday night (9 p.m. ET/6 p.m. PT).

In the bout before Garcia faces Redkach, former IBF/IBO/WBA 154-pound champ Jarrett Hurd (23-1, 16 KOs), of Accokeek, Maryland, and Francisco Santana (25-7-1, 12 KOs), of Santa Barbara, California, are scheduled to meet in a 10-rounder. Philadelphia’s Stephen Fulton (17-0, 8 KOs) and Ukraine’s Arnold Khegai (16-0-1, 10 KOs) are set to fight for the IBO super bantamweight championship in Showtime’s 12-round opening bout.

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