There are a number of players that are fatigued
Uncapped back row forward Robbie Diack will make his Ireland debut against Argentina in Resistancia on Saturday.
South African-born Diack, 28, fills in for the injured Peter O'Mahony - with fellow back row forward Jordi Murphy also poised to make his first Test start.
Diack played for Emerging Ireland in last year's Tbilisi Cup and lined out for the Ireland Wolfhounds against England Saxons in January.
There are two further uncapped players on the bench, as Connacht duo Kieran Marmion and Rodney Ah You hope to claim their first caps.
The front row sees Jack McGrath win his ninth cap - and second start - alongside hooker Rory Best and Mike Ross.
Captain Paul O'Connell is partnered in the second row by the 22-year-old Iain Henderson, who is the youngest member of the matchday squad alongside Marmion (also 22).
It will be O'Connell's 100th Test match - 93 appearances for Ireland and seven with the British & Irish Lions.
He is the fourth Irishman to play in 100 international games after Brian O'Driscoll (141), Ronan O'Gara (130) and John Hayes (107).
The back row is made up of Ulster teammates Diack and Chris Henry with Leinster's Jordi Murphy, who is making his first start at this level, wearing the No.8 jersey.
Conor Murray (No.9) and Jonathan Sexton (No.10) start at halfback, with Luke Marshall and Darren Cave in the centre.
Marshall and Cave are two of the seven Ulstermen in the selected team - their biggest representation in an Irish side since the 2007 World Cup warm-up game against Scotland.
The back three is made up of wings Simon Zebo and Andrew Trimble and Munster's Felix Jones at fullback. Zebo and Jones are picking up their first caps since last year's mid-year tour.
"It was difficult in some ways, but it was actually relatively easy in other ways," coach Joe Schmidt said.
"There are a number of players that are fatigued from the Pro12 Final, there are a number of players that we wanted to give an opportunity. We have this one window to really do that.
"The year-end series is going to be immeasurably tougher with South Africa and Australia, but it's going to be very, very tough here, and one of the things that you want to find out is how the players cope in a tough environment.
"It will be hostile [on Saturday], it's a place where a Test match hasn't been before so the local population will be very much behind the Argentinians."
Ireland: 15 Felix Jones, 14 Andrew Trimble, 13 Darren Cave, 12 Luke Marshall, 11 Simon Zebo, 10 Jonathan Sexton, 9 Conor Murray, 8 Jordi Murphy, 7 Chris Henry, 6 Robbie Diack, 5 Paul O'Connell (captain), 4 Iain Henderson, 3 Mike Ross, 2 Rory Best, 1 Jack McGrath.
Replacements: 16 Damien Varley, 17 Dave Kilcoyne, 18 Rodney Ah You, 19 Devin Toner, 20 Jamie Heaslip, 21 Kieran Marmion, 22 Ian Madigan, 23 Fergus McFadden.
Date: Saturday, June 7
Venue: Estadio Centenario, Resistencia
Kick-off: 15.40 (18.40 GMT; 19.40 Irish time)
Referee: Glen Jackson (New Zealand)
Assistant referees: Mike Fraser (New Zealand), Jaco van Heerden (South Africa)
TMO: Shaun Veldsman (South Africa)