But the cruiserweight boxer has invited the Latvian world champion to target them in next Saturday's world title fight for the IBF and The Ring belts at the Gold Coast Convention Centre.

"It was pretty ****ing painful," Opetaia told AAP of the moment his punch in a sparring session tore the cartilage from his ribs.

"It was a big injury; I have two battle scars now ... they're pretty much bullseyes for him, but we're ready.

"I'm fit and strong and there's no pain there, so let's get it on."

Opetaia, 26, made history when he qualified for the 2012 Olympics at just 16.

A low-key professional career has progressed without a slip-up, Opetaia undefeated and managing 17 stoppages in 21 wins.

His rib injury and a bout of COVID-19 for Briedis have forced this fight's date to be changed twice, coincidentally now set to fall exactly five years after Jeff Horn shocked Manny Pacquiao just up the road at Suncorp Stadium.

Victory against the hardened 37-year-old would see Opetaia emerge from the shadows of former amateur mate Tim Tszyu and recently dethroned George Kambosos Jnr as Australia's only current male world boxing world champion.

"I've ticked all the boxes, got to do everything really young and I'm still only 26," he said.

"I knew from my first fight when I was eight years old that I was capable of fighting the best in the world and I'm almost there.

"Now I get to prove to everyone what I've always known.

"My time (in the spotlight) will come; once I win a world title I'll be the only one and it'll speak for itself."

Briedis (28-1) has beaten Marco Huck, Krzysztof Glowacki, Manuel Charr, and Yuniel Dorticos, the five victories coming since his only loss in 2018 to current heavyweight champion Oleksander Usyk.

The 37-year-old touched down on the Gold Coast this week in terrific shape but, with Pacquiao's shock loss in Brisbane on the mind, wary of the task.

"Everybody who comes into Australia, it's a gamble," he said.

"As a tourist, very, very nice country, like Miami, but this is not business for me; it's my love, what I do, my life."

Australian Associated Press