But the little-known Tuggeranong Vikings playmaker has vowed to throw everything he's got into chasing his childhood Super Rugby dream at an age when some players are contemplating retirement.

Thompson and New Zealand's Wharenui Hawera are locked in a flyhalf showdown as the pair aim to impress at pre-season training with a contract on the line in Christian Lealiifano's absence.

Both are keen to help fill the void left by Lealiifano as he continues his fight against leukaemia, but their futures won't be decided until early next year.

Brumbies coach Stephen Larkham said the pair had a "genuine opportunity" to step up and take the ACT reins, while youngster Nick Jooste is also in contention for No.10 duties.

Thompson offers experience as a 29-year-old rookie, while Hawera turned heads in the New Zealand provincial competition with his playmaking flair.

Thompson usually spends his days working for Aristocrat as a technician and is pencilled in to return to work on December 28 when the rest of the Brumbies squad takes a holiday.

But he has taken confidence from Tuggeranong and Canberra Vikings teammate Lealiifano.

"It's been a dream of mine to play Super Rugby and I haven't quite got there, but this is the closest I've been," Thompson said.

"I'll take it with both hands and give it a crack. I spoke to Christian and he said he was backing me to have a good crack.

"It's pretty awesome hearing that from him. If you get the chance you've got to be your own player and work on the things [you need to improve]."

"With me and [Hawera], it's good competition and hard at the same time because it's one opportunity for the both of us.

"It's pretty hard for a No.10 to be picked up at the age of 29. But if my body's up to it and I'm playing well enough, why not?"

Larkham has requested training footage of the duo while he juggles his Wallabies assistant coaching duties on the spring tour of Europe.

"It really is a genuine opportunity," Larkham told Fairfax Media from London.

"We've got guys in the pre-season to bolster numbers and there is a chance there for a contract.

"Isaac has been around for a while and he is a bit older but Super Rugby is right there.

"Wharenui is a little bit younger and has been on the fringes of New Zealand Super Rugby teams and he's a really attacking player with a great skill-set."

Hawera was unsure he would get a chance to play Super Rugby after New Zealand teams filled their playmaker spots months ago.

The exciting 23-year-old was considering a switch to the New Zealand sevens set-up but Lealiifano's illness and the departure of Matt Toomua has opened a door in Canberra and he's keen to take his opportunity.

"I came over here with an open mind. It's been tough so far but I've enjoyed the experience," Hawera said.

"When this opportunity came up I wanted to grab it with two hands and take it. There is a chance here so I'm looking to put my best foot forward and see what happens.

"Hopefully I can add a bit of flair ... I get along well with Isaac so we're helping each other through this process and we'll see what happens."