Tuesday's opponents Argentina or the Pumitas as they are called, are seeded 3 in and last year defeated Ireland in this competition. To achieve that ranking they defeated South Africa, 34-30 in a third place play-off, despite trailing 13-0 at half-time.
They opened their account this time around with a 43-10 win over Italy, scoring seven tries in the process and collecting three cards, one red and two yellow, flanker Juan Leguizamon sent off for an alleged head-butting incident.
On Sunday evening the Irish squad made the twenty minute coach journey to Cambus Lang RFC for their training session where team manager David Haslett announced the side for the game against Argentina.
Haslett confirmed that the management had the opportunity to view a video of the Argentina/Italy game and the impression was that the Irish will face an altogether different challenge from the one posed by Tonga on Friday.
" I would say that there is much more structure, much more experience to this Argentina side than Tonga. " Haslett said.
"The Argentines have a powerful pack, very big, as indeed were Tonga, but Argentina look to be much more organised, more structured whereas the Tongans tended to play more off-the-cuff stuff.
"Besides that pack they have two experienced halves in (scrum-half) Alfredo Lalanne and whichever 10, Gaston Graco or Alfredo Cordone, they decide to go with. Cordone played against Italy, scored a try and kicked their points.
"All three were in the side last year and besides these they have loads of pace out wide."
Ireland Under 21.
15. Andrew Finn (Dolphin)14. Richard Lane (UCC)13. John Hearty (Blackrock Coll)12. Glen Telford (Dungannon)11. Tommy Bowe (Queens Uni)10. Gareth Steenson (Queens Uni) 9. Tomas O'Leary (Cork Constitution) 1. John Wickham (Clontarf) 2. Denis Fogarty (Cork Constitution) 3. Declan Fitzpatrick (Belfast Harlequins) 4. David Gannon (Blackrock Coll) capt
Replacements16. Conor Geoghegan (UCD)17. Keith Doyle (UCD)18. Neil McComb (Dundee HSFP)19. Anthony Kavanagh (Garryowen)20. Robbie Shaw (Wasps)21. Michael Glancy (Loughborough Uni)22. Breiffne O'Donnell (UL Bohemians).