CJ Stander and Rob Kearney have been passed fit to play for Ireland against Australia, while captain Rory Best will win his 100th cap on Saturday (5.30pm, live on RTÉ Radio 1 and RTÉ2).
Stander and Kearney both went through return-to-play protocols during the week, having suffered knocks to the head against New Zealand last Saturday, and were selected at flanker and full-back respectively.
"Rob trained for the first time today and we just trained him away quietly because that’s how you train them back," coach Joe Schmidt told reporters.
"He’s still got another 48 hours to really build himself into this weekend’s match, same with CJ Stander."
Simon Zebo suffered cramp at the end of last week's game and so starts on the bench with Keith Earls coming in to the starting 15.
"Simon Zebo was very sore after the [New Zealand] game," said the Kiwi.
"He’s taken two or three days and trained today but probably didn’t train flat out, he’s still got another 48 hours to recover and we’re hoping he’ll be 100% by Saturday.
"With that little bit of lingering doubt, Keith Earls brings a freshness to the group and hopefully that will add a bit of vitality.
"Also Keith’s roundly experienced and gives us a bit of midfield cover should we need so that versatility is not too bad to have."
Second row Iain Henderson gets his first start of the November series, while Garry Ringrose will win his third cap, coming in for the injured Robbie Henshaw.
"His selection is a reflection of his performance last week. I thought Garry stepped in and did incredibly well.
"He managed to get himself up in the top three tacklers in the game which is a fair reflection of the game.
"He also slipped a couple of tackles and he got one line break and almost got another couple.
"It’s another opportunity to invest in Garry.
"We’ve obviously had him in camp for the last year-and-a-half at different times and he’s been a bit of a long-term investment and we want to take this opportunity to develop him a little bit further."
At out-half Paddy Jackson gets the nod in the absence of Johnny Sexton, with Joey Carbery on the replacements bench.
Best, 34, joins an illustrious list of centurions alongside Brian O'Driscoll, Paul O'Connell, Ronan O'Gara and John Hayes.
Earlier, Michael Cheika made seven changes to the Wallabies side for the clash in Dublin 4.
Ireland: Rob Kearney, Andrew Trimble, Jared Payne, Garry Ringrose, Keith Earls, Paddy Jackson, Conor Murray; Jack McGrath, Rory Best (capt), Tadhg Furlong, Devin Toner, Iain Henderson, CJ Stander, Sean O’Brien, Jamie Heaslip.
Replacements: Sean Cronin, Cian Healy, Finlay Bealham, Ultan Dillane, Josh van der Flier, Kieran Marmion, Joey Carbery, Simon Zebo.
Watch Ireland v Australia (kick-off 5.30pm) live on RTÉ2, listen live on Radio 1's Saturday Sport and follow RTE Sport Online's live blog