Scrum half Paul Marshall has become the second Irish player to fall foul of injury at the IRB Under-21 World Championship in France.
The Ballynahinch player injured his hand in Tuesday's 26-22 defeat to Argentina. He was replaced by UCC's Duncan Williams after 66 minutes, and has since flown home for treatment. Marshall has transferred to Belfast Harlequins for next season.
Dublin University's Matthew D'Arcy has taken the vacant scrum half spot in the Irish U-21 squad. A former High School pupil and a member of the Leinster Under-21 championship winning side, he linked up with the panel in Auvergne on Wednesday afternoon.
Flanker Ross Noonan (hamstring) was forced out of the squad at the weekend with his place going to his UCC colleague Michael Essex. Ireland face Georgia in Issoire on Saturday afternoon (kick-off 3.00pm Irish time).