Head coach Mike Ruddock has handed Cork Constitution scrum half Ryan Foley his first start at Under-20 level. He will link up at half-back with the ever-present Ross Byrne, who scored 20 points in the opening two pool games.
Darragh Moloney makes way for the returning Stephen Gardiner from Lansdowne in the second row, while Josh Murphy and Rory Moloney - both capped at Under-19 level this season - have been brought into the back row alongside captain Jack O'Donoghue.
Ireland can book a first ever semi-final spot with a bonus point victory over Fiji, because even if Pool B leaders France were to beat Wales the 11 points Ruddock's side would accumulate would be more than the runner-ups in the other two pools can reach.
However, Ruddock is not taking anything for granted as the Fijians have shown glimpses of attacking flair and pushed France hard in the first half last Friday to go in at half-time only 8-0 behind before ultimately losing 37-5.
"In our last two matches we got the result against Wales and were very competitive against France, so to sum it up I would say we have got a little better with each game," admitted Ruddock.
"It would be a big achievement (to reach the semi-finals) but we don't want to get carried away with the outcome. We have really focused on the process and our game-plan, tactically and mentally we have got to bring it."
Meanwhile, the Irish squad took time out from their match preparations to participate in the Junior World Championship legacy programme. They were given a warm welcome at Pukekohe Rugby Club on Sunday - some of the players are pictured below with the Pukekohe Kapa Haka group.
There will be live coverage of the Ireland v Fiji match on TG4 in the early hours of Tuesday morning (kick-off 1.35pm local time/2.35am Irish time), with the full match repeated at 12.30pm and highlights at 7.30pm.
IRELAND UNDER-20 Team & Replacements (v Fiji Under-20s, 2014 IRB Junior World Championship - Pool B, QBE Stadium, Auckland, New Zealand, Tuesday, June 10, kick-off 1.35pm local time/2.35am Irish time):
15. Cian Kelleher (Lansdowne/Leinster)
14. Ciaran Gaffney (Galwegians/Connacht)
13. Garry Ringrose (UCD/Leinster)
12. Dan Goggin (Young Munster/Munster)
11. Alex Wootton (Garryowen/Munster)
10. Ross Byrne (UCD/Leinster)
9. Ryan Foley (Cork Constitution/Munster)
2. Max Abbott (Cork Constitution/Munster)
3. Rory Burke (Cork Constitution/Munster)
4. Stephen Gardiner (Lansdowne/Leinster)
5. Ross Molony (UCD/Leinster)
6. Josh Murphy (UCD/Leinster)
7. Rory Moloney (Buccaneers/Connacht)
8. Jack O'Donoghue (UL Bohemians/Munster) (capt)
16. Dylan Donnellan (UCD/Leinster)
17. Denis Coulson (Lansdowne/Leinster)
18. Oisin Heffernan (Lansdowne/Leinster)
19. Darragh Moloney (Cork Constitution/Munster)
20. Frankie Taggart (Belfast Harlequins/Ulster)
21. Nick McCarthy (UCD/Leinster)
22. Conor McKeon (Lansdowne/Leinster)
23. Harrison Brewer (Terenure College/Leinster)
IRELAND - POOL B FIXTURES/RESULTS:
Monday, June 2: France 19 IRELAND 13, QBE Stadium, Auckland
Friday, June 6: Wales 21 IRELAND 35, ECOLight Stadium, Pukekohe
Tuesday, June 10: IRELAND v Fiji, QBE Stadium, Auckland, 1.35pm local time/2.35am Irish time (live TG4) (Buy match tickets)
For the full fixtures list, please click here.