Cusack's aunt, Loretta Dorman, met him in Sydney with her 1988 hockey gold medal to give the uncompromising back-rower a taste of what it's like to be an Olympic champion.

It was the perfect last-minute motivation for 23-year-old Cusack who will step on to the rugby sevens stage in Rio less than a year after turning down a contract with the ACT Brumbies.

But the best part of his injury-riddled journey is that he gets to do it alongside Canberra schoolboy rival Lewis Holland after the pair spent their youth bashing into each other.

The Olympics will begin with a bang at the opening ceremony on Saturday morning (Australian time) before the focus turns to individual sports and the pursuit of glory.

The Australian men's sevens team will begin its campaign against France on Wednesday morning.

Rugby sevens is making its Olympic debut but the Games have been in Cusack's blood since he was a child.

"To see my auntie win Olympic gold and how much that meant to her and the family, it was a big thing for me to try to replicate what she did and put my claim forward," Cusack said.

"Everyone's going over with that goal of winning gold. I've seen it. I want to experience it and I'm fortunate enough to have a Commonwealth Games bronze medal.

"But to go to an Olympic Games, the next step and the bigger brother, to chase that gold medal is something that I won't be taking lightly and I'll never forget.

"I've listened to [Dorman] and how much it meant to her. I'm looking to add to what she's already done."

Australia has sent a 410-strong team to Rio and it is hoped they can force their way back into the top five on the medal tally after a disappointing performance in London four years ago.

Cusack is one of 20 Canberra athletes competing across nine sports, including BMX queen Caroline Buchanan and former mechanic Sharni Williams.

Cusack's hopes of competing in Rio were almost ruined by a wrist injury that forced him to miss almost all of Australia's selection tournaments.

The former Marist College student had a chance to join the Brumbies Super Rugby squad at the end of last year, but opted to put all of his focus into sevens.

"I've always taken pride out of taking on challenges and different life experiences," Cusack said.

"Sevens is a format that allows you to do a lot of travel and go to different events ... although my ambition is and always will be in Super Rugby, to be going to Rio is massive.

"It reaffirms my decision four years ago to take a chance on sevens and constant decisions throughout that journey."

Cusack has been based in Sydney as part of the full-time sevens squad.

But every couple of weeks he jumped in his car with teammate and Braidwood junior Holland to visit family and friends in Canberra.

Cusack and Holland have been playing rugby against each other since they were 10 years old, but their Marist College and St Edmund's College divide still runs deep.

"I was always up against Tommy, he had to wear headgear because his mum wouldn't let him play without it. That must be the Marist side coming out in him," Holland said.

"He was always lanky and as white as the clouds, but he could do everything.

"To be going to an Olympics together is a massive achievement and it's good that we've been side by side through it all. Home is our little safe haven."

RIO-BOUND CANBERRA ATHLETES

Athletics: Melissa Breen (100 metres), Zoe Buckman (1500 metres), Chris Erickson (50 kilometre walk), Tanya Holliday (20 kilometre walk), Brendon Reading (50 kilometre walk), Kelsey-Lee Roberts (javelin), Brett Robinson (5000 metres), Rachel Tallent (20 kilometre walk), Jared Tallent (20 kilometre walk and 50 kilometre walk), Lauren Wells (400 metre hurdles).

Basketball: Patrick Mills, Marianna Tolo, Stephanie Talbot.

Boxing: Shelley Watts.

Cycling: Nathan Hart (team sprint), Gracie Elvin (road), Caroline Buchanan (BMX), Rebecca Henderson (mountain bike), Daniel McConnell (mountain bike).

Soccer: Michelle Heyman, Lydia Williams.

Hockey: Edwina Bone, Emily Smith, Andrew Charter, Glenn Turner.

Rowing: Kim Brennan (single scull).

Rugby sevens: Sharni Williams, Tom Cusack, Lewis Holland.

Swimming: Alicia Coutts (200 metre individual medley), Matt Abood (50 metres freestyle, 4x100 metre freestyle relay).