Paul O'Connell seems unlikely to play again this season after admitting defeat in his efforts to avoid surgery on his injured back.
The Munster and Ireland lock forward has only played twice since May because of the problem and his province confirmed that he was going to have an operation after their 24-10 win over Ulster.
O'Connell, 33, had been due to see a specialist in the New Year before making a decision whether to go under the knife but that has been brought forward after consultation between Irish RFU and Munster medical staffs.
He has not played since the round two Heineken Cup game against Edinburgh at Thomond Park in October.
It is the latest in a long list of injury setbacks O'Connell has suffered in recent years and, as well as meaning him missing the Six Nations, it puts his participation in the Lions tour of South Africa next summer in serious jeopardy as well.
The Young Munster player captained the Lions on their last tour to South Africa in 2009 and was high on Warren Gatland's list of candidates to lead the touring party to Australia.
He spent nine months on the sidelines with a groin injury that needed several diagnoses, and missed Ireland's tour of New Zealand last summer with a knee problem that lasted into the current season as well.