Ireland flanker Josh van der Flier will miss the rest of the season with a serious knee injury.
The Leinster back-row forward hobbled out of Saturday's 15-13 Six Nations win against France in Paris, and the Irish Rugby Football Union announced on Monday that he has now been ruled out for the remainder of the campaign.
Van der Flier had held off the charge of in-form Leinster team-mate Dan Leavy to take the starting number seven shirt at the Stade de France, and had started well before injury ended his afternoon.
Ireland are already hoping British and Irish Lions flanker Sean O'Brien can recover from a hip injury to feature at some point in the Six Nations, so Joe Schmidt's men can do without further hindrance in their back-row stocks.
Van der Flier's injury also represents a significant blow to Leinster, who must do without the 24-year-old for the rest of a highly-promising season, with a Champions Cup quarter-final against Saracens in April still in the offing.
Ireland appear to have emerged otherwise unscathed from their gruelling, last-gasp win in Paris, where Johnny Sexton dropped an overtime goal to snatch victory.
Fit-again Munster prop Dave Kilcoyne has returned to the squad to boost the front-row options, but Andrew Conway remains sidelined with a knee concern of his own.