George Dyer will start at tighthead prop, while All Blacks Aidan Ross, Samisoni Taukei’aho and Brodie Retallick complete the tight five.
The loose forwards are unchanged with the ever-consistent Samipeni Finau, co-captain Sam Cane, and Luke Jacobson at No 8.
Brad Weber commands the starting halfback role, with impact to come off the bench from the dangerous Cortez Ratima, who boasts a remarkable passing accuracy of 99.3 per cent across the 15 games he has played this season.
The top points-scorer and goal-kicker in the competition, Damian McKenzie runs out at first five with Josh Ioane as support, while Anton Lienert-Brown joins Nankivell in the midfield, and the dynamic Etene Nanai-Seturo, Emoni Narawa and Shaun Stevenson complete a potent back three.
Tyrone Thompson enters the line-up as the reserve hooker, with Ollie Norris named alongside John Ryan to support at prop. Pita Gus Sowakula and Naitoa Ah Kuoi will provide their usual power off the bench at loose forward or in the second row.
“It should be a hell of a game,” McMillan says.
The semifinal kicks off at 7.05pm on Saturday at FMG Stadium Waikato.
Gallagher Chiefs team to face the Brumbies
1. Aidan Ross (72)
2. Samisoni Taukei’aho (75)
3. George Dyer (19)
4. Brodie Retallick (126)
5. Tupou Vaa’i (42)
6. Samipeni Finau (30)
7. Sam Cane (Co-Captain, 148)
8. Luke Jacobson (61)
9. Brad Weber (Co-Captain 121)
10. Damian McKenzie (109)
11. Etene Nanai-Seturo (42)
12. Anton Lienert-Brown (104)
13. Alex Nankivell (68)
14. Emoni Narawa (27)
15. Shaun Stevenson (82)
Reserves
16. Tyrone Thompson (13)
17. Ollie Norris (43)
18. John Ryan (15)
19. Naitoa Ah Kuoi (47)
20. Pita Gus Sowakula (67)
21. Cortez Ratima (24)
22. Josh Ioane (9)
23. Rameka Poihipi (28)