But the Canberra-raised flanker has launched straight into the gruelling campaign with his playful moustache, coming first in the Super Rugby club's time trial last week.

Pulling on the Brumbies jumper was a "childhood dream" for the 23-year-old and he's not going to let this chance slip.

"[My fitness] is something that I pride myself on," Cusack said. "I like to be the fittest there and I like to set a good example in that sense.

"I feel that's a representation of how I want to play my game – to be more versatile and a bit more adaptable in running off the backs."

Through the NRC he also became painfully aware that to mix it with the best in the 15-a-side game he's going to have to put on some weight.

"I'm somewhat on the lighter side coming from sevens so I'm probably about three or four kilograms too light."

Cusack wants to turn his 12-month Brumbies audition into a long-term future as he attempts to force his way into a back row already boasting Scott Fardy, Jordan Smiler, Jarrad Butler, Chris Alcock, Lolo Fakaosilea and Tom Staniforth.

This competition for spots extends to the back line where the role of chief playmaker is far from being crowned.

New Zealand five-eighth Wharenui Hawera is doing his best to earn a full-time contract and veteran Isaac Thompson is also staking his claim.

While the opportunity to sign an external established number 10 remains a possibility, Cusack says this level of competition for spots will only result in a strong team come 2017.

"It's all positive and it's all welcome competition," he said. "A successful team doesn't really thrive without any competition and I think that's where the Brumbies are in a pretty good position at this stage.

"We've got a lot of young kids coming through with a lot of skill and that's really going to play into the hands of the style the Brumbies look to play.

"Everyone wants to perform and everyone wants to put their hand up for selection."

In just the second week of pre-season the Brumbies are already focusing on contact and scrum-based drill, which has been a pleasant surprise for new recruit Nic Mayhew.

The former Auckland Blues loosehead prop is another fresh face at the Super Rugby side who said he crossed the Tasman wanting to slot into the highly regarded forward pack.

"I haven't done this much contact early on [in my previous pre-seasons]. I'm used to a lot of running but it has been good, it's a crucial part of the game," Mayhew said.

"Doing that early on is going to pay off later down the track."