It hardly seems like the nerves are getting to the 22-year-old prospect ahead of his first Super Rugby game in more than 15 months.

But the butterflies are there as he prepares to fill the void left by a Brumbies star desperate to get his hands on the Wallabies' No. 15 jersey.

Hansen admits he didn't get much sleep the night after Brumbies coach Dan McKellar told him he would start at fullback against the Melbourne Rebels at Canberra Stadium on Saturday.

"I'm pretty nervous but I'm nervous for pretty much every game I play, so I would worry if I wasn't nervous," Hansen said.

MORE BRUMBIES NEWS

So how does he keep them under control before he meets a Matt To'omua-led Rebels backline sure to put him under the test as they look to capitalise on the new 50-22 rule.

"I'll wake up at probably 10 or 11am, I'll see how I'm feeling. That's a pretty good sleep in," Hansen grinned.

"Bacon and egg rolls, chill out, watch a bit of TV, a bit of pasta before the game with a fair bit of salt on that so I don't cramp later. I used to have heaps of superstitions but I've reeled them in."

McKellar has given Hansen a licence to back himself but wants the rising star to avid overplaying his hand as he looks for the consistency that can make him a Super Rugby regular.

"Banksy has helped me a lot with that, he's prepared me pretty well. I'm keen to get out there and just start the game really," Hansen said.

"It's unreal. We're pretty good mates off the field as well, so he has helped me heaps. He's obviously had Wallaby experience as well, so just picking his brain and finding out what he has gone through has been really helpful.

"It's been a long time coming but we're all just itching to get out there."

Brumbies skipper Allan Alaalatoa has backed Hansen to thrive as he prepares to fill the void left by Banks, adamant the Gungahlin product has all the tools he needs.

"He'll be awesome. He has trained really well throughout the pre-season, he is someone who was unbelievable throughout the beginning of the year," Alaalatoa said.

"He has been given the first shot, he has been given his opportunity. For him, it's all about backing himself and backing his process, and he always has his brothers behind him to support him.

"I'm really looking forward to seeing him and how he is going to shine."

SUPER RUGBY AU ROUND ONE

Saturday: ACT Brumbies v Melbourne Rebels at Canberra Stadium, 7.15pm.

Brumbies: 1. James Slipper, 2. Folau Faingaa, 3. Allan Alaalatoa, 4. Darcy Swain, 5. Murray Douglas, 6. Rob Valetini, 7. Tom Cusack, 8. Pete Samu, 9. Joe Powell, 10. Noah Lolesio, 11. Tom Wright, 12. Irae Simone, 13. Tevita Kuridrani, 14. Andy Muirhead, 15. Mack Hansen. Reserves. 16. Connal McInerney, 17. Scott Sio, 18. Tom Ross, 19. Tom Cusack, 20. Lachlan McCaffrey, 21. Issak Fines, 22. Bayley Kuenzle, 23. Len Ikitau.

Rebels: 1. Matt Gibbon, 2. Jordan Uelese, 3. Pone Fa'amausili, 4. Matt Philip, 5. Michael Stolberg, 6. Josh Kemeny, 7. Richard Hardwick, 8. Michael Wells, 9. Ryan Louwrens, 10. Matt To'omua, 11. Marika Koroibete, 12. Billy Meakes, 13. Reece Hodge, 14. Andrew Kellaway, 15. Dane Haylett-Petty. Reserves: 16. Efitusi Maafu, 17. Cameron Orr, 18. Jermaine Ainsley, 19. Trevor Hosea, 20. Esei Haangana, 221. Rob Leota, 22. Frank Lomani, 23. Andrew Deegan.