A string of injuries to hookers, including to Tatafu Polota-Nau on his return to the team after a long lay-off against the Pumas last week, forced McKenzie to bring the 33-year-old journeyman on board as back-up to James Hanson and Saia Faingaa.
A foot injury to Peter Betham has also depleted McKenzie's stocks of wingers and Joe Tomane comes back into the squad after a lengthy spell on the sidelines, while stalwart Adam Ashley-Cooper is fit again after missing the Pumas match.
Will Genia, once-rated as the best scrumhalf in the world, also returns to the Wallabies squad after ankle surgery, although Nick Phipps and Nic White are ahead of him in the queue for the number nine shirt.
McKenzie has decided not to bring in extra cover at number eight with Wycliff Palu again ruled out by concussion but prop Benn Robinson gets his chance to play his first test of the year on the tour.
The 30-year-old, who has won 66 caps, brings a wealth of experience to reinforce the front row for what are certain to be attritional tests against two big packs of forwards.
"It's pleasing to be able to bring in some experienced guys for what will be an extremely challenging tour of South Africa and Argentina," McKenzie said in a news release. "Collectively, we add almost 250 games of test experience to our squad through the inclusion of Adam, Will, Benn and Saia.
"They've all had good exposure to our programme this year, so we expect them to be able to contribute immediately when we get into camp."
Australia are third in the standings after narrow homes wins over South Africa and Argentina over the last two weeks and play the Springboks in Cape Town on Sept. 27 before meeting the Pumas in Mendoza a week later to round out the championship.
Squad:
Forwards - Ben McCalman, Scott Higginbotham, Michael Hooper (captain), Matt Hodgson, Scott Fardy, James Horwill, Rob Simmons, Sam Carter, Pek Cowan, Benn Robinson, Ben Alexander, Sekope Kepu, James Slipper, Saia Faingaa, James Hanson, Josh Mann-Rea.
Backs - Israel Folau, Rob Horne, Joe Tomane, Adam Ashley-Cooper, Tevita Kuridrani, Christian Leali'ifano, Matt Toomua, Kurtley Beale, Bernard Foley, Will Genia, Nic White, Nick Phipps.
(Reporting by Nick Mulvenney, editing by Greg Stutchbury)
