Haunted Harrison on redemption mission against Tszyu

Tony Harrison has revealed how the harrowing memory of his late father-trainer looking shattered ringside following a last-up loss to Jermell Charlo is driving his redemption bid against Tim Tszyu.

Ali Salaam died of COVID-19, aged just 59, four months after Harrison relinquished the WBC super-welterweight belt to Charlo in December 2019.

Harrison walked in to a huge left hook in the 11th round and was knocked down a second time before the fight in Ontario was stopped.

Harrison (29-3-1, 23KO) remains the only boxer to have conquered his fellow American, having scored a unanimous points decision over Charlo (35-1-1, 19KO) a year earlier in Brooklyn.

The 32-year-old is desperate to secure a trilogy fight against Charlo with victory over Tszyu (21-0, 15KO) on Sunday after watching his father - a professional welterweight himself from 1984 to '89 - go to his grave believing he'd let his son down.

"I watched the look on my father's face when we came up short the second time facing Charlo," Harrison told AAP ahead of his showdown with Tszyu for the WBO interim super-welterweight strap at Sydney's Qudos Bank Arena.

"I watched the disappointment, not for me losing the fight but the disappointment that he had as a trainer when we lost that fight.

"My dad wasn't a soft guy, he wasn't sentimental but I watched the hurt on his face after that fight.

"He doubted himself and he was saying to himself: 'Maybe I need to get a new trainer'. He wasn't telling me that but that was just what I observed from his actions.

"He wanted to give me someone who could maybe take me over the edge. If I could tell my father just one thing while he was here, I would say 'Pops, you was enough'."

The haunting experience is why Harrison pledged to himself that night to earn another crack at Charlo.

The winner of the Tszyu-Harrison stoush will get that opportunity later this year in a unification blockbuster in Las Vegas.

"That's my whole game plan. My whole game plan is to get back that fight, just for my father's sake to show him why he was good enough," Harrison said.

"And I'm going to show you Sunday why he was good enough.

"We had it hard some times but he was definitely enough for me.

"I just wish he was here because the dedication I've got for this fight to get that Charlo fight is everything."