Munster captain Peter O'Mahony has been ruled out for the rest of the season after undergoing shoulder surgery on Wednesday morning.
The 24-year-old suffered the injury during the early stages of Munster's Heineken Cup quarter-final victory over Toulouse last weekend.
Munster said in a statement: "Peter O'Mahony is to undergo reconstructive shoulder surgery this morning and is ruled out for the remainder of the season.
"O'Mahony travelled to Dublin late yesterday evening for a review with the specialist, and following the consultation it was confirmed that the Munster captain required surgery on his left shoulder.
"Peter sustained the injury in the opening 20 minutes of Munster's 47-23 victory against Toulouse on Saturday after he over-extended his shoulder."
O'Mahony will miss Munster's Heineken Cup semi-final against Toulon at the end of April and the final rounds of the RaboDirect Pro12, as well as Ireland's summer tour of Argentina.