Tszyu's eyes on the prize, blocking out family sideshow

His eyes firmly on the prize, Tim Tszyu is refusing to be swept up in the family sideshow as he chases a rare slice of sporting history.

Tszyu's super-welterweight showdown with American Tony Harrison in Sydney on Sunday presents the 28-year-old with the opportunity to become only the sixth boxer ever to emulate his father and become a world champion.

While his legendary, Moscow-based dad Kostya won't be at Qudos Bank Arena, Tszyu's younger brother Nikita will feature on the same card for the first time.

Tszyu has been a ringside regular at Nikita's previous four professional fights, but knows he can't afford to burn any emotional energy watching his undefeated sibling this time around against fellow Australian Bo Belbin.

"Boxing's such a selfish sport that unfortunately all you have to do is think about yourself," Tszyu said as the countdown to his date with destiny continued with open sessions on Thursday at Bondi Beach.

"For this fight it's different. It's a different feeling just because I'm (also) stepping into the ring and my sole focus is myself.

"I'm not worried about Nikita on Sunday because that's his job. I can't focus on that. I've got too many things to think about right now to think about Nikita.

"I'm locked in, locked in. This is a big moment in my career, 28 years in the making so I'm locked in.

"I believe that this is the stage that I was born for."

Harrison (29-3-1, 21KO) has already scaled the heights and been world champion, but Tszyu (21-0, 15KO) is growing increasingly confident he will drop the Detroit danger man.

"I truly, truly believe it and a lot of people will witness because I know it's going to happen. It's not if it happens, it's when it happens," said Tszyu, dismissing Harrison's brashness and bravado.

"Wait til he feels the first jab. Then it's all going to change.

"See that water? I'm going to drown him and suck the life out of him.

"I feel in the terminator mode now. Get someone in front of me."

Should he follow through on his promise, Tszyu will land a shot at undisputed divisional champion Jermell Charlo, whose only defeat so far came against Harrison in 2018.

Tszyu was to have fought Charlo in Las Vegas in January but the Texan broke two bones in his left hand during training at Christmas.

Tszyu is desperate to see off Harrison and secure another chance, some time this year, to join Kostya as the only father and son to be crowned unified world champions.

Tszyu also believes Nikita because of his "obsession" can be a world champion.

"That's the goal," he told AAP.

"Nikita's got a long, long way to go. He's got years of grinding and years of fighting and fighting anyone.

"That will all come down to him.

"(But) he will get the job done on Sunday. I believe that."