Ireland lock Paul O'Connell has been ruled out of the RBS 6 Nations clash with Italy because of a fractured thumb.
O'Connell sustained the damaged to his right hand in Saturday's 19-18 victory over Scotland at Murrayfield.
The Munster forward, who was man of the match in the record 43-13 triumph over England, will see a specialist on Monday to assess the extent of the damage.
The loss of O'Connell is a major blow to Ireland, who were thrust back into the RBS 6 Nations title race by England's 26-18 triumph over France on Sunday afternoon.
One of five nominees for the 2006 IRB player of the year award, the 27-year-old hardman is an inspirational figure and his presence will be missed against the ever-physical Italians.
Mick O'Driscoll is in pole position to replace his provincial team-mate in the starting line-up with Leinster's Trevor Hogan a leading contender to fill the vacancy on the bench.
Marcus Horan is continuing his rehabilitation from the calf strain that forced him to withdraw against Scotland and could yet be fit for the trip to Rome.
But Isaac Boss, another player forced to miss Ireland's Triple Crown celebrations in Edinburgh, will not recover from his shoulder injury in time to face the Azzurri.
Should Ireland, France and England win next weekend, the championship will be decided on points difference.
But Ireland coach Eddie O'Sullivan insists his side's assignment at the Stadio Flaminio is no foregone conclusion given Italy's controversial 23-20 victory against Wales.
O'Sullivan said: "The result today opens up the championship heading into the final weekend.
"We are now in a position where ourselves, England and France all have the chance to win the Six Nations.
"England played very well and the result will put pressure on France in the final game against Scotland who will certainly be no pushovers.
"Italy's victory against Wales puts a different complexion on our final game.
"As I've always said, Italy are a good side and are now playing with a huge amount of belief.
"England also have a tough game against a Welsh side that are going to be fighting for their lives in Cardiff.
"I do not think that there are any easy games in the final weekend of the championship."