The Wallabies have been forced to call Brandon Paenga-Amosa into the team for the final test against the British & Irish Lions after hookers Dave Porecki and Matt Faessler picked up injuries in training.
Porecki, who started last week's second test, suffered a heel injury and Faessler, who started the first, picked up a calf issue in training on Thursday.
Billy Pollock moves up from the replacements to start in place of Porecki on Saturday, while Paenga-Amosa will come off the bench as the Wallabies look to grab a consolation win after losing the first two tests.
Captain Harry Wilson said the team had great faith in the powerful Paenga-Amosa, who played the last of his 20 tests against Ireland last November.
"Brandon joined us yesterday afternoon after a bit of a tough Thursday training session, it's obviously gutting to lose great players in Porecki and Fez," the No 8 told reporters at Stadium Australia on Friday.
"But we've got a lot of confidence in BPA, he's been around this group for quite a long time over the last year and he's already faced the Lions three times. So he's got a lot of confidence and ... he has fit in very quickly."
Paenga-Amosa, who faced the Lions in tour matches for Western Force, the Australia-New Zealand selection and the First Nations-Pasifika XV, will bring power to the front row but his lineout throwing has sometimes been wayward.
Coach Joe Schmidt had already been forced into three changes to his team by injuries but Wilson said it had been good to have fresh faces Taniela Tupou and Dylan Pietsch in the matchday squad.
"What they've given us is fresh legs on the training park, fresh energy, more chatter around the training field. Just been nice and they're just raring to go," he said.
"They've had to watch the last two test matches so they're all very excited at this opportunity and I've got no doubt they'll take it."
The fourth change Schmidt made in his initial selection was a call-up for Nic White, who announced on Thursday that he would be retiring from test rugby after Saturday's match.
The Wallabies players all wore fake moustaches at Friday's training session in honour of the scrumhalf's famously hairy upper lip.
"He's a competitor, and he's loved by the group," Wilson said. "He will be missed in this gold jersey, because he really does represent what it is to be a Wallaby."
Wilson admitted the players had been crushed after losing the second test to a last-minute try last Saturday but spirits had risen during the week.
"We just want to keep improving. We want to keep being a better team. We need to play an 80-minute game and get the result which I think we deserve for each other."
Lions searching for best performance
The Lions will empty the tank in search of a complete performance they've been seeking throughout the tour on Saturday, assistant coach John Dalziel said.
The test series is already sewn up with Lions victories in Brisbane and Melbourne, but going into the tour finale in Sydney the tourists still feel they have not played their best rugby.
Scotland forwards coach Dalziel said the squad were naturally tired after two months on the road but also determined to bid farewell to Australia with a 10th win and an 80-minute performance.
"Well for us it's the only way to end this now, isn't it?" he told reporters at Stadium Australia.
"We don't want anything to derail it. We know it's going to be incredibly hard work. It'll be more wet playing here. So we have just got to find that energy and go again and get that performance that we all want."
Ireland prop Tadhg Furlong would have more cause than many to feel fatigued having played in six of the nine matches so far in one of the most demanding positions on the park.
The determination of the Lions to close out the tour in style means the 32-year-old will suit up again for his sixth start of the tour, and his last in a Lions shirt.
In doing so, Furlong will match Wales lock Alun Wyn Jones' record of nine consecutive Lions test starts going back to the series opener against the All Blacks in 2017.
"It is a little bit emotional, the Lions have played a massive part in my career," the tighthead told reporters on Thursday.
"It has shaped the way I play the game and think about the game. I know this Lions tour will be me closing the book on the Lions. I don't want it to end. It is a special thing to be a Lion."
Australia
Revised team: 15 Tom Wright, 14 Max Jorgensen, 13 Joseph Suaalii, 12 Len Ikitau, 11 Dylan Pietsch, 10 Tom Lynagh, 9 Nic White, 8 Harry Wilson, 7 Fraser McReight, 6 Tom Hooper, 5 Will Skelton, 4 Nick Frost, 3 Taniela Tupou, 2 Billy Pollard, 1 James Slipper
Replacements: 16 Brandon Paenga-Amosa, 17 Angus Bell, 18 Zane Nonggorr, 19 Jeremy Williams, 20 Langi Gleeson, 21 Tate McDermott, 22 Ben Donaldson, 23 Andrew Kellaway
