Ireland captain Paul O'Connell and scrum-half Conor Murray have been ruled out of the rest of the Six Nations.
Lock O'Connell suffered medial ligament damage after twisting his left knee in Sunday's 17-17 draw with France and will be sidelined for up to six weeks.
Murray will be out for at least three weeks after being stretchered off in Paris with bruising to a knee joint.
Connacht forward Mike McCarthy and Munster scrum-half Tomas O'Leary have been added to the Irish squad as cover.
A scan showed that O'Connell injured his medial collateral ligament and he will have a three to six weeks recovery period.
Murray sustained his injury when he fell awkwardly on his right knee, and he was replaced after 59 minutes.
The Munster pair will miss the Saturday's encounter with Scotland at the Aviva Stadium and the final Six Nations game away to England a week later.
O'Connell is also a doubt for Munster's Heineken Cup quarter-final against Ulster on 8 April although Murray should be fit for the Thomond Park clash.