There are only three survivors from the Wallabies side that lost to Wales for Saturday's crucial clash against Uruguay.
Georgia will hope to keep their slim hopes of Rugby World Cup progression intact against a Fiji side humbled by Uruguay last time out.
Robbie Henshaw is yet to feature for Ireland at the 2019 Rugby World Cup and Joe Schmidt remains reluctant to risk him against Russia.
Rassie Erasmus is focusing on a "major forward battle" against Italy, but South Africa have lost utility back Jesse Kriel to injury.
Only four players remain from Ireland's stunning defeat to Japan, as Johnny Sexton captains his country for the first time against Russia.
The United States were hammered by England in their Rugby World Cup opener - France now hope to do the same to them on Wednesday.
Scotland got back on track against Samoa on Monday, giving Gregor Townsend great encouragement after an opening defeat.
Even Beauden Barrett's standards can be improved by a sibling rivalry, according to Steve Hansen, as they prepare for Canada.
Pool A remains wide open at the Rugby World Cup after Scotland beat Samoa to join their opponents and Ireland on one win from two matches.
The Barrett siblings become just the second trio of brothers to start in a World Cup match after the Tongan Vunipola brothers in 1995.