There are also changes on the bench with Ospreys flanker Justin Tipuric coming in along with Rhys Webb and Richard Hibbard.
And caretaker boss Rob Howley is confident the Welsh can bounce back from the 27-19 defeat in their tour opener.
He said: "After the first Test Australia are obviously in the ascendancy, but the tour is not over by any means and we have all to play for on Saturday.
"We are bringing three very experienced players into the pack, all three made an impact from the bench during the first Test which has justified their selection in the starting line-up this weekend.
"We were also impressed with the performances of Ashley Beck, Justin Tipuric, Richard Hibbard and Rhys Webb on Tuesday night [against the Brumbies] and they have each very much played themselves into the squad.
"Having played two matches now on Australian soil we have acclimatised and are ready for another huge challenge this Saturday in Melbourne."
Meanwhile, Leinster prop Mike Ross returns to the Irish team for their second Test against New Zealand in place of Ulster's Declan Fitzpatrick.
He will be joined by Leinster teammates Gordon D'Arcy and Kevin McLaughlin who come into the centre and back row respectively, while Andrew Trimble slots in on the wing ahead of Simon Zebo.
63x46.png){kind=logo}