He will be replaced in the squad by Oisin Heffernan, while UL Bohemians and Munster 'A' back rower Jack O'Donoghue will take over as captain of the side.
Centre Peter Robb is out with an ankle injury he picked up during the Under-20 warm-up game against Scotland a fortnight ago. Harrison Brewer has been called into the squad.
Ian Fitzpatrick comes into the side to replace full-back/winger David Busby who picked up a knee injury during a training session.
Ireland share Pool B with France, Fiji and Wales and open their tournament against France next Monday (June 2) at QBE Stadium in Auckland.
Ireland's pool games will be broadcast live on TG4 along with the Junior World Championship semi-finals and final.
IRELAND UNDER-20 Squad (2014 IRB Junior World Championship, New Zealand, June 2-20):
Max Abbott (Cork Constitution/Munster)
Rory Burke (Cork Constitution/Munster)
Ross Byrne (UCD/Leinster)
Harrison Brewer (Terenure College/Leinster)
Denis Coulson (Lansdowne/Leinster)
Billy Dardis (UCD/Leinster) *
Diarmaid Dee (Young Munster/Munster)*
Dylan Donnellan (UCD/Leinster)*
Peter Dooley (Lansdowne/Leinster)
Ryan Foley (Cork Constitution/Munster) *
Ian Fitzpatrick (Lansdowne/Leinster)
Ciaran Gaffney (Galwegians/Connacht) *
Stephen Gardiner (Lansdowne/Leinster)
Dan Goggin (Young Munster/Munster)
Oisin Heffernan (Lansdowne/Leinster)
Cian Kelleher (Lansdowne/Leinster)
Nick McCarthy (UCD/Leinster)
Conor McKeon (Lansdowne/Leinster)
Darragh Moloney (Cork Constitution/Munster) *
Rory Moloney (Buccaneers/Connacht)
Ross Molony (UCD/Leinster)
Jack O'Donoghue (UL Bohemians/Munster) (capt)
Garry Ringrose (UCD/Leinster)
Frankie Taggart (Belfast Harlequins/Ulster)
Peadar Timmins (UCD/Leinster)
Craig Trenier (Terenure College/Leinster) *
Alex Wootton (Garryowen/Munster)
* Denotes uncapped player at international Under-20 level
IRELAND - POOL B FIXTURES:
Monday, June 2: France v IRELAND, QBE Stadium, Auckland, 5.35pm local time/6.35am Irish time (live TG4) (Buy match tickets)
Friday, June 6: Wales v IRELAND, ECOLight Stadium, Pukekohe, 5.35pm local time/6.35am Irish time (live TG4) (Buy match tickets)
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.
Related Links -
TG4 To Show Ireland U-20 Games Live From New Zealand
Ireland Under-20s End Championship In Eighth Place