Ireland's CJ Stander and Rob Kearney were passed fit to face Australia on Saturday as coach Joe Schmidt made four changes from the side that lost to New Zealand in a bruising encounter last weekend.
Flyhalf Jonathan Sexton and centre Robbie Henshaw were ruled out earlier this week after suffering a hamstring problem and concussion respectively in the 21-9 loss, while hurt wing Simon Zebo moves to the bench and lock Donnacha Ryan sits it out.
Fullback Kearney and back rower Stander were doubtful after also receiving knocks to the head. Paddy Jackson, Garry Ringrose and Keith Earls come in to the backline while Iain Henderson returns to the pack where captain Rory Best is set to become the fifth Irishman to reach 100 caps.
"Rob (Kearney) trained for the first time quietly today and he's still got another 48 hours to really build himself into this match. Same with CJ Stander," Schmidt told a news conference on Thursday.
"Donnacha Ryan has put in a huge shift, he's played in all three games and he was pretty fatigued. Simon Zebo was very sore after the game, he trained today but probably not flat out and we're hopeful that he'll be 100 per cent by Saturday."
Schmidt said 21-year-old centre Ringrose, starting for just the second time, would get another valuable learning experience against Tevita Kuridrani and Reece Hodge after coming off the bench early and doing "incredibly well" against New Zealand.
"We've obviously had him in camp for the last year-and-a-half at different times so he's been a bit of a long-term investment that we want to take this opportunity to develop a little bit further," Schmidt said.
After winning in South Africa for the first time in June and claiming their first win in 111 years of trying against the All Blacks earlier this month, Ireland are aiming for a trio of southern hemisphere scalps in six months but also have one eye on February's Six Nations.
"I'm massively keen that we get a good performance, there are a few things that we want to work really hard on this weekend that will give us a little bit of feedback for the Six Nations. That's the big tournament," Schmidt said.
Team (15-1): Rob Kearney, Andrew Trimble, Jared Payne, Garry Ringrose, Keith Earls, Paddy Jackson, Conor Murray; Jamie Heaslip, Sean O'Brien, CJ Stander, Devin Toner, Iain Henderson, Tadhg Furlong, Rory Best (captain), Jack McGrath
