The inclusion of Robinson and Morahan represent the only two changes made to the starting side which recorded a 34-20, four-try bonus point win against the Lions at the weekend.
Morahan comes into the number 15 jersey to replace injured playmaker Ben Lucas, who wasn’t able to overcome a groin injury he sustained early in the second half against the Lions.
Lucas became a late withdrawal from the Reds’ 23-man touring squad with flyhalf Dallan Murphy travelling with the team to Canberra to take a place on the bench.
Robinson has been selected at blindside flanker where he will partner rising star Liam Gill in a backrow that includes Scott Higginbotham at No.8.
The Reds maintain the same tight-five from last week with a front-row of Greg Holmes, Saia Faingaa and James Slipper joining locks Rob Simmons and James Horwill.
Morahan is the sole change to a backline that features playmaking duo Will Genia and Quade Cooper; a centre pairing of Mike Harris and Anthony Faingaa; and wingers Digby Ioane and Dom Shipperley.
“The breakdown has been an important part of the game all year and we’ll continue to make it the focus it deserves by starting Liam and Beau in this critical game,” McKenzie said.
“It’s a strategy that worked well for us when we defeated the Brumbies earlier this year and Beau is raring to go after being given last week off to bring him back to 100 percent fitness.
“Ben came very close to being right for this week but we made a decision that it would be best to not risk agitating his injury further.”
A win on Saturday will see the Reds gain possession of the prestigious Rod Macqueen Cup for the first time.
Queensland Reds team to play Brumbies
1. Greg Holmes
2. Saia Faingaa
3. James Slipper
4. Rob Simmons
5. James Horwill (c)
6. Beau Robinson
7. Liam Gill
8. Scott Higginbotham
9. Will Genia
10. Quade Cooper
11. Digby Ioane
12. Mike Harris
13. Anthony Faingaa
14. Dom Shipperley
15. Luke Morahan
16. James Hanson
17. Ben Daley
18. Adam Wallace-Harrison
19. Jake Schatz
20. Nick Frisby
21. Dallan Murphy
22. Chris F'Sautia