It was a nervous wait to see if he had done enough to make the team.
"I knew I was in the running for the team, but I wasn't too sure. There were a couple of other players that had good results too, so I was about 50/50", Trimble said.
"It was a big relief."
Along with brother Max, Mum Gaye is also active in the local squash scene, as a social player and administrator for Squash Northland.
Finn attributes recent improvements to his game to working hard on his fitness in the off season (summer).
Dad John provides valuable family support too, and on the technical side of things, there are Finn's Auckland-based coaches Glen Wilson and Paul Hornsby.
In Whangarei, regular matches with Brent Lewis are a key part of his training, and Ryan Chestnut provides valuable personal training input.
If there is no tournament, there are two hours training a day, ranging from skill work to strength and fitness.
He also travels to Auckland once a week to work with Wilson and Hornsby.
Trimble isn't the only Whangarei connection in the NZ team - Sam Sayes is another product of the Whangarei Squash Club's Junior Academy, who began in Whangarei before moving to Auckland.
The team also features Dame Susan Devoy's son Jamie Oakley (Tauranga), Scott Galloway (Wellington) and Matthew Lucente (Auckland - non travelling reserve).
The World Junior Men and Junior Girls teams events are played in alternate years.
Last year, Whangarei Squash Club member Abbie Palmer was part of the NZ girls team that competed in the Netherlands.
Trimble has already had a taste of representing his country when he was selected as part of the New Zealand Junior Team that won the transtasman Series on the Gold Coast earlier this year.