Ulster hooker Tom Stewart will captain the Ireland XV side and is one of ten Test-capped internationals in the starting team to face Spain on Saturday (5pm Irish time).
Senior internationals Michael Lowry, Robert Baloucoune and Shayne Bolton are selected in the back three for the game in Leganes, outside Madrid.
Former Ireland Under-20 international Dan Kelly will partner Ulster's Jude Postlethwaite in midfield, while Leinster out-half Harry Byrne and Connacht's Ben Murphy form the half-back pairing.
In the pack, Michael Milne, captain Stewart and Tom O'Toole make up an all-Test front row, with Evan O'Connell and Darragh Murray, who also made his senior debut during the summer tour, in the second row.
Alex Soroka, Ruadhan Quinn and Paul Boyle complete the starting team in the back row.
Lee Barron, Alex Usanov, Scott Wilson, Diarmuid Mangan and David McCann are the forward reinforcements, while Nathan Doak, Cathal Forde and Zac Ward are the backline options on the bench.
All the Ireland squad naturally harbour ambitions to break into Andy Farrell's panel but head coach Cullie Tucker believes that performing as a collective is the best way for the hopefuls to catch the eye of the senior coach.
The Connacht assistant said: "It's probably one of the biggest challenges, but they're experienced and knowledgeable enough as players to know that performance collectively will mean as an individual they'll kick on.
"Putting our stock into the team and how we play collectively both sides of the ball will breed opportunity for them.
"For us it's been 'team first' all week, us performing collectively and that'll put the best foot forward for the people on the pitch to hopefully put their hands up in the future."
Spain are ranked 15th in the world and have qualified for the World Cup in Australia in 2027.
Tucker (above) believes these games, like the one Ireland 'A’ played against England ‘A’ last spring, are vital for the development of the fringe players.
"It's not just a match," said the Limerick man. "It's five days to prepare yourself for a game.
"It's pushing yourself out of your comfort zone to connect with other people from other provinces, both on and off the pitch.
"You learn a lot about them. As coaches, we learn so much about them during the week and then the proof of the pudding will be in the performance at the weekend.
"I think stretching players and pushing them out of our comfort zone as much as we can is where we need to put them so they can put their hand up to kick on and challenge the guys in the senior squad."
The game will be played at Estadio Municipal de Butarque and will be available to watch on RugbyPass TV.
Ireland XV: Michael Lowry; Robert Baloucoune, Jude Postlethwaite, Dan Kelly, Shayne Bolton; Harry Byrne, Ben Murphy; Michael Milne, Tom Stewart (capt), Tom O'Toole; Evan O’Connell, Darragh Murray; Alex Soroka, Ruadhan Quinn, Paul Boyle.
Replacements: Lee Barron, Alex Usanov, Scott Wilson, Diarmuid Mangan, David McCann, Nathan Doak, Cathal Forde, Zac Ward.
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