Manny Pacquiao's long-time trainer is adamant Australian boxer Justis Huni has the same "lethal combination" of strength and speed as the former eight-division world champion.

Huni has returned to Justin Fortune's Hollywood gym ahead of his next fight, against New Zealand's Kiki Leutele in Brisbane on November 4.

His most recent visits to the United States were hampered by serious bouts of COVID-19 but this time Huni is fully fit and enjoying sparring sessions against world-ranked heavyweight Frank Sanchez and ex-world champion Dillian Whyte.

An Australian former heavyweight fighter, Fortune was Pacquiao's strength and conditioning coach for more than 20 years.

"(It's the) same as with working with Manny; he's very strong but he's ridiculously fast," Fortune said of Huni on Tuesday.

"Put those together, it's a lethal combination and Justis has the same deal in the heavyweight division."

Huni, 23, is 6-0 but has repeatedly faced criticism for his lack of power, with rivals adamant he still fights like an amateur and lacks a knockout punch.

The heavyweight has pencilled in three bouts by March next year, after which he hopes to have built a world ranking and with it the right to contend for a global title.

Huni has consistently laughed off concerns about his punch but admits working on his power has been a big focus of his time with Fortune.

Fortune reckons Huni has improved as a boxer since their last meeting about a year ago and has time on his side as he looks to graduate into a world-title contender.

"You're a heavyweight for god's sake, that's what they're meant to do - go in there and hurt people," Fortune said.

"But he's fast and strong enough to use it all to his advantage; he thinks, he plans an attack and executes it well.

"He's 23, and won't peak until he's 26, 27.

"His promoter will move him properly and ... move up the ladder.

"When we're ready the shot will come for the title."