The Victorian is looking to bring home the WBA middleweight belt when he takes on Lara on the undercard of the Tim Tszyu-Sebastian Fundora blockbuster fight on March 31 (AEDT).

Zerafa says it's his big sister's dream to see him win a world title, but thought she would be doing it from her Melbourne home after undergoing a round of radiation treatment last week.

But the mother-of-three shocked him by turning up in Las Vegas to see the 32-year-old in the biggest fight of his career.

"It was an amazing surprise and I'm so grateful that she's made the trip because I know what she's going through," Zerafa told AAP.

"I don't know how she's done it - I don't think she's told the doctor and hospital.

"She's given me the extra motivation come fight time - I'm dedicating the fight to her and hopefully God does the rest for me and hopefully I bring home that world title.

"She's in the fight of her life so 12 rounds with Lara is nothing compared to that.

"Hopefully we can get her into the ring and we share the moment together."

Zerafa hasn't fought since November 2022 and was embroiled in an ugly split with his trainer Sam Labruna before cutting ties with his US promoter.

The 32-year-old, who has been training under Filipino future Hall of Famer Nonito Donaire, said the time waiting for a world-title fight had made him more hungry.

"The preparation has been unreal - I've had 10 weeks with Nonito Donaire and we've been pushing the pace," Zerafa said.

"Having Nonito by my side has just taken me to another level mentally, he's a very spiritual fighter and he's tamed my inner beast so it's time to unleash.

"I feel amazing - physically, mentally and emotionally and I'm ready to go."

Lara is aged 40 and hasn't fought for almost two years but possesses an impressive record of 29-3 (17KO), including a split-decision loss to superstar Saul 'Canelo' Alvarez.

"I respect what he's done but he's getting on, he's held on to the belt for way too long and he's just looking for a pay day with Danny Garcia or one of those guys and I need to upset the plan and take what's rightfully mine.

"I know it's going to be a hard fight but I'm prepared for it."

Lara said he respected Zerafa (31-4 1KO) despite this being his first world title fight.

"If he wasn't at my level he wouldn't be inside the ring," Lara said.

"I've fought against guys like him and I respect them, they're contenders for a reason."

Australian Associated Press