Former Scarlet Dwayne Peel starts with Scarlets scrum half Martin Roberts taking up Peel's position on the bench in the only other change to the match day 22 which downed the Pumas. Cardiff Blues' Gareth Cooper takes up regional duties on Tuesday evening against the Wallabies.
Gatland said: "We were pretty pleased with the performance against Argentina, we matched them up front, our defence held up well and we are starting to show a more clinical edge in attack."
Wales' record against Australia shows two wins, a draw and three losses in the last six meetings and although Gatland is no slave to the history books he does concede his side enjoy playing the Wallabies.
"They are one of the top three teams in world rugby and we have no right to expect anything other than the sternest of tests - both physically and mentally - on Saturday, but we feel we are up to it."
WALES: James Hook; Leigh Halfpenny, Jamie Roberts, Jonathan Davies, Shane Williams; Stephen Jones, Dwayne Peel; Gethin Jenkins, Matthew Rees, Paul James, Alun-Wyn Jones, Luke Charteris, Andy Powell, Martyn Williams, Ryan Jones (captain).
Replacements: Huw Bennett, Duncan Jones, Jonathan Thomas, Dan Lydiate, Martin Roberts, Andrew Bishop, Tom James