Ireland scrum-half Luke McGrath will miss the Six Nations after being ruled out for up to eight weeks with a knee ligament injury.
The Leinster man hobbled off during the province’s 29-13 win over Toulouse on Saturday.
Scrum-halves John Cooney and Kieran Marmion are also currently nursing injuries but could return in time for the tournament opener.
Ireland host England on 2 February in their opening game.