Munster's Craig Casey is to undergo knee surgery this week after picking up a serious injury in their investec Champions Cup loss to Castres on Friday night.
The scrumhalf was forced off after half-an-hour of play.
The extent of the injury will be confirmed after the procedure but it's expected he will miss 4-to-6 week.
Elsewhere winger Thaakir Abrahams dislocated his shoulder in the game and may also need surgery.
While Peter O’Mahony is suffering with a calf issue and may miss their URC inter-pro with Ulster on Friday.