Cathal Sheridan's season looks to be over after the 25-year-old fractured his forearm playing for Munster against the Ospreys.
Sheridan has played an excellent role working as Conor Murray's back-up during the Pro12 and Heineken Cup, but now looks unlikely to feature again this season.
"Cathal Sheridan underwent surgery yesterday evening after breaking a bone in his right forearm in Sunday's RaboDirect PRO12 victory against Ospreys," read a Munster statement.
"After further examination yesterday morning it was revealed that the scrum-half sustained a broken bone and he required surgery yesterday evening.
"Sheridan is expected to be ruled out for approximately three to four months."
The injury leaves Munster with Duncan Williams and Gerry Hurley in reserve behind Murray, who is currently away playing in the Six Nations.