The pair's fight is scheduled for three two-minute rounds.
"I know Luke will have endurance so I'm going to have to rely on my speed and power," Karauria, 39, said.
"I've been waiting for an opportunity like this for a while and it's for a good cause. I did a bit of boxing in Wairoa when I was six because my dad [Ken Karauria] was a Golden Gloves fighter," he said.
As expected the pair boasted evenly-matched confidence levels.
"I'm not going in there to get knocked out," remarked Karauria.
"Likewise," Ottley said as the pair came to face to face during a photo shoot at Combat Room in Hastings.
Karauria is being trained by former Hawke's Bay age group softball coach Julian Nohokau who was a more than handy amateur boxer in his younger days.
Magpies halfback Chris Eaton, who will also fight on the night, and his brother Kim are organising the event as a fundraiser for the Jarrod Cunningham Trust and Kim's Auckland-based 9-year-old niece Lili Reynolds, who was diagnosed with a brain tumour when she was five.
"Lili is battling well and the money will go towards her treatment," Kim said.
Last year Lili was chosen by the Make a Wish Foundation and Team New Zealand to present the Duchess of Cambridge with a posy of flowers before she went sailing in Auckland.
The feature bout will see professional kickboxer Angus Benson take on another kickboxer, Shaun Rankin, who is no stranger to success on the Hawke's Bay charity boxing scene. They were teammates in the Maraenui division three rugby side last season after Benson stepped down a couple of grades from the Napier Technical premiers so he could devote more time to his kickboxing.
Former Magpie Andy Barham, who has also fought on the charity boxing scene in the past, is assisting the Eaton brothers with the event.
"I've talked to most of the boys who are taking part and they are amped for the pre-season and this will benefit the club rugby scene. Rather than saying here we go again they can't wait to get to their rugby trainings because they have more of an aerobic base from their boxing training," Barham said.