Brumbies coach Dan McKellar has full faith in rookie Mack Hansen after picking him to start at fullback against the Rebels.
The Gungahlin Eagles back featured for the Brumbies against the Waratahs but played just four minutes off the bench in that game.
With Tom Banks failing to shake off a foot injury he picked up during the season shutdown, Hansen will have his first Brumbies start on Saturday.
McKellar said he had no hesitation in throwing Hansen in the deep end with the no.15 jersey.
"He was rewarded last year with the South African tour, took him to Argentina for the semi-final as well and that was all reward off the back of the work he's put in at training," he said.
"He's done that consistently well, he understands what's required now to play well at this level and he's ready to go.
"We talk about when we expose our young players that they're ready to perform and Mack's certainly in that category."
Minor injuries have also ruled out halfback Ryan Lonergan (ankle) and Solomone Kata (hamstring) from Saturday's clash.
Kata's injury meant the decision of whittling of three impressive wingers down to two starters was made for the coaches, with Tom Wright and Andy Muirhead starting on the edges.
Lonergan's absence opens the door for Issak Fines to make his Brumbies debut off the pine.
James Slipper will start at loosehead over Scott Sio, combining with Folau Fainga'a and Allan Alaalatoa.
Darcy Swain will team up with Murray Douglas in the second row for the first time in 2020 while Tom Cusack starts at openside with Locky McCaffrey and Will Miller on the bench.
The Brumbies held off the fast-finishing Rebels earlier this year in their round two clash, after which Rebels coach Dave Wessels accused the Brumbies of slowing down the play.
It's a comment that McKellar hasn't forgotten and was quick to refute when asked about their approach to the game on Thursday.
"It's certainly not a tactic of ours," he said.
"Rugby's a pretty unique game, you can approach it in different ways through the course of any game.
"If you look at some of the statistics at the end of seven weeks, we'd scored more tries than anyone, our back three had scored plenty of those tries, we only scored four maul tries this year and most points in the competition.
"If you look back at that game (against the Rebels), we scored four tries in the first half so the game's going to stop and slow down if you're taking conversions, we can't stop that, and a couple in the second half.
"Do we like to play attacking rugby and do we like to go to set piece scrum, lineout and maul and challenge teams in that area of the game as well? 100 per cent.
"Will we change that? No."
The Brumbies take on the Rebels on Saturday July 4 at GIO Stadium, kicking off at 7:15pm AEST, LIVE on Foxtel, Foxtel Now and Kayo Sports. Buy a Kayo subscription here.
Brumbies to face Rebels
1. James Slipper
2. Folau Fainga'a
3. Allan Alaalatoa (c)
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
16. Connal McInerney
17. Scott Sio
18. Tom Ross
19. Lachlan McCaffrey
20. Will Miller
21. Issak Fines*
22. Bayley Kuenzle
23. Len Ikitau