Dublin - Josh van der Flier has been ruled out for the rest of the season after suffering a knee injury in Ireland's Six Nations win against France, the Irish Rugby Football Union said Monday.
The Leinster flanker sustained a serious knee ligament injury during Saturday's match in Paris and was replaced by his provincial teammate Dan Leavy.
The 24-year-old was filling the considerable vacuum left by injured British and Irish Lions star Sean O'Brien.
Ireland host Italy in their second game of the championship in Dublin on Saturday.
The IRFU added that Munster prop Dave Kilcoyne has rejoined the squad after being left out for the France game, while back-row Jack O'Donoghue and uncapped wing Barry Daly will train with the team during the early part of the week.
Wing Andrew Conway will miss the Italy match to continue his recovery from injury at Munster.
Flyhalf Johnny Sexton scored a dramatic late drop goal to earn the Irish a 15-13 victory against France, after the hosts looked to have snatched the win themselves thanks to a dazzling try from wing Teddy Thomas eight minutes from time.