Allen Clarke's youngsters overcame Scotland 44-15 to lift the RBS Under-20 6 Nations trophy in Athlone in March, and a victory on Monday afternoon would see them finish ninth overall at the Argentinian event.
The Irish management have continued their squad rotation policy for this 9th-10th place play-off. There are three changes in the backs, with Eoin Griffin and Nevin Spence restored to the centre berths and John Cooney returning at scrum half.
Spence has recovered from a back injury to take over from David McSharry at inside centre.
Hat-trick hero from the Samoan game, Andrew Boyle, retains his place on the right wing, while his back-three colleagues Andrew Conway and Simon Zebo are set for their fifth successive tournament starts. Boyle and Conway are both still 18.
Hooker and team captain Niall Annett and number 8 Paddy Butler have also been ever-present in the Ireland starting line-up.
Up front, there are two changes as second row David O'Callaghan and flanker Dominic Ryan return.
Robin O'Sullivan, who was called into the squad in place of senior tourist Rhys Ruddock, and Mike Kelliher, an injury replacement for Darren Hudson (shoulder), are new inclusions on the replacements bench.
IRELAND UNDER-20 Team & Replacements (v Scotland U-20s, IRB Junior World Championship, Club Atletico Estudiantes, Parana, Monday, June 21, kick-off 12pm local time/4pm Irish time):
15 - Andrew Conway (Blackrock College/Leinster)
14 - Andrew Boyle (UCD/Leinster)
13 - Eoin Griffin (Corinthians/Connacht)
12 - Nevin Spence (Ballynahinch/Ulster)
11 - Simon Zebo (Cork Constitution/Munster)
10 - Noel Reid (UCD/Leinster)
9 - John Cooney (UCD/Leinster)
1 - Bryan Cagney (UCC/Munster)
3 - Martin Moore (Lansdowne/Leinster)
4 - David O'Callaghan (UCC/Munster)
5 - Brian Hayes (Cork Constitution/Munster)
6 - Dominic Ryan (Lansdowne/Leinster)
7 - Brian O'Hara (UL Bohemians/Munster)
8 - Paddy Butler (Shannon/Munster)
16 - David Doyle (UCD/Leinster)
17 - Denis Buckley (Corinthians/Connacht)
18 - Jordi Murphy (Blackrock College/Leinster)
19 - Robin O'Sullivan (Bective Rangers/Leinster)
20 - Michael Heaney (Belfast Harlequins/Ulster)
21 - James McKinney (Queen's University/Ulster)
22 - Mike Kelliher (Richmond/Munster)
IRELAND'S IRB JUNIOR WORLD CHAMPIONSHIP RESULTS:
Saturday, June 5: Ireland 22 France 25, Estadio El Coloso del Parque, Rosario
Wednesday, June 9: Ireland 21 England 36, Estadio El Coloso del Parque, Rosario
Sunday, June 13: Argentina 24 Ireland 21, Estadio El Coloso del Parque, Rosario
Thursday, June 17: Ireland 37 Samoa 10, Club Atletico Estudiantes, Parana