A scan after Ireland's 12-6 defeat by England in Dublin uncovered a stress injury in a bone in the Leinster player's foot, putting him out of action for an estimated six weeks, the Irish Rugby Football Union said in a statement.
Earlier this week Ireland fly-half Jonny Sexton and lock Mike McCarthy were ruled out of the next Six Nations match against Scotland with injuries.
Prop Cian Healy has been suspended for two matches for stamping on England prop Dan Cole, while winger Simon Zebo will miss the remainder of the tournament with a broken foot.
Ireland, who beat Wales in their opening Six Nations match, next face Scotland in Edinburgh on February 24. They will then play France in Dublin and Italy in Rome.
