Johnny Sexton has been ruled out of this Saturday's Nations Cup fixture against England because of a hamstring injury.
Sexton underwent a scan on the injury picked up against Wales and will not be fit for the game.
The IRFU did not disclose any further detail on the complaint in the injury update.
Robbie Henshaw picked up an abductor strain and is also ruled out on Saturday.
Billy Burns was forced off with a head injury against Wales and will follow the HIA return to play protocols.
Jacob Stockdale is set to return to training later this week as he tries to overcome a calf problem.
Iain Henderson will return to training today and Shane Daly is back training fully this week.
Follow England v Ireland this Saturday via our live blog on RTÉ.ie/sport and the RTÉ News app, watch live on RTÉ One from 2pm, or listen to live updates on RTÉ Radio 1's Saturday Sport.