While 2005 Tall Blacks squad member Trousdell stopped playing this year to focus on his teaching commitments and to set up a sports academy, he has still been training with his Melbourne club so he can stay in shape for next month's match which will double as a fundraiser for the Te Anahera O Te Rangi Charitable Trust which 2017 world kickboxing champion O'Brien and wife Theresa formed in memory of their late daughter.
Trousdell agreed his HBHS side should have too much ammunition for the NBHS side and pointed out many players from the 1999 HBHS team which reached the semifinals of their national competition combined to beat the HBHS 2014 squad during a team reunion five years ago.
"All the boys still had the same techniques as they had back in the day."
Trousdell also agreed the antics of the respective coaches, Curtis Wooten for HBHS and Paul Trass for NBHS, will no doubt prove almost as entertaining as the on-court action.
Some other members of the HBHS team will also travel from Aussie for the match and O'Brien's brother and fellow former Hawk Henare O'Brien will return from Bali.
Another member of the side, former Hawk Thomas Bartlett, who has been organising the HBHS team, believed Patrick O'Brien was the best secondary schools player in the country in 1998.
Knee injuries suffered at the end of that season slowed him down the following year when future Tall Black and Breakers legend Kirk Penney captured the MVP award while playing for Westlake Boys' College.
"That 1999 team was our best one. That was the year we beat Church College who had not been beaten for the previous eight years. We should have made the final and when we lost our semifinal I remember Patrick punching the walls in our changing room ... that's how competitive he was," Bartlett recalled.
Former Hawk Roger McPherson has organised the NBHS side. He said his players were quick to respond and eager to support the fixture.
One player he couldn't secure was former Tall Black, Breakers and Hawks point guard Paul Henare because of his coaching commitments in Japan. In Henare's absence McPherson delivered his tribute to O'Brien at his funeral.
Henare said while O'Brien wouldn't want to be known as a philanthropist the definition of a philanthropist summed him up perfectly.
"A philanthropist is someone who gives money or gifts to charities or helps needy people in other ways."
Henare recalled his coaching days with the Hawks when O'Brien came on board as the team trainer, which he did for nothing as a favour to him.
There wasn't enough room for everyone at the hotel when it came to finals weekend in Wellington so O'Brien made his own way to the capital and slept on the floor of one of the player's rooms so he could continue to support the team in any way he could.
McPherson and O'Brien were teammates in the Hawks second division side for two years before stepping up to the NBL side together.
"I obviously played against him more often than with him during our school days. I was always scared shit less of him but when he was on our team we were almost unbeatable."
McPherson coached O'Brien's youngest son Elijah at seventh grade rugby this year and pointed out he has a personality similar to his father's ... "a very feisty player".
O'Brien's brother Henare pointed out, in addition to the match between the old boys, there will also be a game between the current NBHS and HBHS squads, a three-on three fixture and an auction of basketball and kickboxing memorabilia.
"As an old boy of HBHS, Pat loved being part of these games and although many of us are now brothers and friends we're dusting off the old basketball gear to honour our bro for his life and the work he did in the community to uplift others," Henare O'Brien said.
O'Brien's work included his annual Battle For Life charity boxing event which focused on raising awareness for suicide prevention, working with the youth in physical fitness programmes to build resilience, focus and strength while also working with men to help them open up and when necessary ask for help.
Teams for the 5pm old boys match:
HBHS: Paul Tu ala-Fatu, Leighton Ashcroft, Thomas Bartlett, Henare O'Brien, Arthur Trousdell, Reece Tu ala-Fatu, Herman Ah KO'ing, Ben South on, Kayne Hawea, Wallace Christian, Paora Winitana.
NBHS: Daniel Evans, James Henare, James Lyver, Janeiro Seu manu, Jeremy Glaser, Roger McPherson, Simon Robert, Jordan Pomona, Damion Davies, Puke Lenden, Conrad Kahu, Regan Spooner, Aidan Daly, Dwayne Davies.