Ireland and Racing Metro are at loggerheads over the severity of Johnny Sexton's thumb injury, casting the fly-half's RBS 6 Nations campaign into doubt.
Ireland's medical team and Paris club Racing's management hold conflicting opinions on Sexton's chances of a quick return from the thumb ligament damage he suffered in Saturday's 13-10 defeat to England at Twickenham.
Sexton's French club ruled the 28-year-old playmaker out of action for between 10 days and six weeks on Thursday, a timescale that could all-but end his Six Nations action.
Ireland bosses later issued a statement rejecting concerns Sexton was already out of contention to face Italy in Dublin on Saturday, March 8.
Racing Metro coach Laurent Labit said through the club's Twitter account: "Johnny Sexton returned from Twickenham with a thumb ligament injury, and will be unavailable between 10 days and six weeks."
The IRFU quickly responded with a statement of their own however, claiming Sexton could yet be fit to face the Azzurri.
"The Ireland medical team have had a consultant hand specialist review Johnny and his scans," read the IRFU statement.
"The ligament damage sustained does not warrant surgery and if Johnny continues his current rate of improvement we would be confident that he will be available for selection against Italy."
Ireland are locked in a four-way fight for the Six Nations title, and losing chief backline architect Sexton would be a major blow.
Head coach Joe Schmidt's men travel to Paris to face France in their final fixture on Saturday, March 15, a week after hosting the Italians.
England, Wales, France and Ireland have all lost one of their three matches in the tournament so far.
Ireland could claim their first title since their 2009 Grand Slam with two more victories.
This latest twist in Sexton's onrunning club-versus-country saga does little to ease the tug-of-war over the former Leinster outside-half that has raged since his move to France last summer.
Schmidt admitted Ireland had "lost control" of Sexton during the autumn Test series, when the star playmaker suffered a hamstring strain on club duty in the middle of the November international schedule.
Sexton left Twickenham on Saturday with his hand in a splint, Schmidt had revealed on Monday.
The 41-cap fly-half returned to France after Ireland's slender England defeat, with Racing expecting him to face Castres in Top 14 league action this weekend.
His Paris club have ruled him out of action though, and cast his Six Nations into doubt in the process.
Schmidt had admitted on Monday he may have looked to rest Sexton against Italy even if he found fitness, in order to keep squad players sharp.
So irrespective of Sexton's fitness, the Ireland coach could turn to Ulster's Paddy Jackson to lead the backline against Italy, with Leinster's Ian Madigan the potential understudy.
Despite Ireland's clear chances of Six Nations glory, Schmidt still rates England as title favourites.
"I think England are going to be the toughest team to beat without a doubt," said Schmidt, warning Ireland to be extremely wary of Italy's threats.
"One of the problems for us is making sure that Italy is our full focus and that it stays that way over the next few days and next week.
"They have a very experienced, very powerful front-row and with Sergio Parisse at number eight he's one of the world's best anchoring that set-piece.
"Across the board I don't think we'll get anything easy against Italy.
"There's a real danger that there's an expectation we'll put a 10 or 20-point margin on them.
"All we want is a margin that gives us the two points for the win, and that will be tough enough.
"Ireland lost to them last year, France lost to them last year: there's a real danger in us looking too far forward.
"We've got to put ourselves in the position to be able to win the championship, and the only way we can do that is to beat Italy first and foremost."