Head coach Gregor Townsend has never been shy of altering a winning side and has done so again, with eight new faces and three positional changes in the matchday XV compared to the 34-13 win over Italy.
Of the four tryscorers last week, three have been left out - Tim Visser because he has not recovered from a rib injury, with Ross Ford and Damien Hoyland rested.
Ford claimed two scores against Italy but has to be satisfied with a place on the bench - if he comes on, he will match the Scotland caps record of 109 held by Chris Paterson.
“It is a brilliant achievement,” said Townsend. “It shows a great level of consistency in a game that has changed a lot.
“Not only that but he has been one of our best performers. Two tries last week were pretty good as well.
“This is a great achievement but we also believe he can carry on playing and have a big role up to and including the World Cup.”
Explaining the changes, he added: “On this tour, we were always keen to make sure that players who were close to selection got an opportunity. A few got it last week, a few who were close to selection get it this week.
“When you put a squad together, you first put a team together that you believe can win. You want to see which players are able to perform at Test level and give them that opportunity - it is up to them after that.
“On this tour, I do believe, a lot of positions are very competitive.”
The changes see the two front-row units swapped in their entirety, the Glasgow trio starting and their Edinburgh counterparts on the bench.
Jonny Gray comes in to partner Ben Toolis in the second row and Hamish Watson has recovered from his groin injury to start at flanker, with John Barclay shifting to the blindside and Ryan Wilson to number eight to accommodate him.
After playing out of position at full-back last week, Duncan Taylor reverts to centre where he partners Alex Dunbar. There is an entirely fresh back three, with Tonks returning at full-back for his first cap since 2015 and Jones on the wing for his first since 2012.
Tonks was a late call-up to the squad but Townsend said he has no worries about including him, even though he spent last season in the Championship with London Irish.
“He has played very well, we have watched a lot of his games,” Townsend insisted.
“The way he plays fits in with the way we have been training; he is a very good passer, makes good decisions, can step up at first or second receiver, has a good kicking game - that balance with Finn [Russell] at 10, left foot, right foot, is important.
“He has played regularly at full-back and one aspect of the Wallabies game, as we saw last week, is their aerial game, especially with Israel Folau being so good in the air - one try [against Fiji] came directly from a kick and they were unlucky not to score a second one in a similar situation.”
• Scotland team to face Australia on Saturday:
G Tonks (London Irish); L Jones (Glasgow), A Dunbar (Glasgow), D Taylor (Saracens), R Hughes (Glasgow); F Russell (Glasgow), A Price (Glasgow); G Reid (Glasgow), F Brown (Glasgow), Z Fagerson (Glasgow), B Toolis (Edinburgh), J Gray (Glasgow), J Barclay (Scarlets), H Watson (Edinburgh), R Wilson (Glasgow).
Replacements: R Ford (Edinburgh), A Dell (Edinburgh), WP Nel (Edinburgh), T Swinson (Glasgow), J Strauss (Glasgow), H Pyrgos (Glasgow), T Jackson (Harlequins), M Scott (Gloucester).