Munster's worst fears were confirmed yesterday when Paul O'Connell was ruled out of the defending champions' Heineken European Cup quarter-final away to Llanelli on March 30th.

The Munster captained had an operation on his fractured thumb last evening and the prognosis is an estimated four to five weeks of recovery, giving him a reasonable chance of making the semi-finals should Munster get that far three weeks subsequently. Their chances of doing so, however, have been significantly damaged.

"It's not a bad injury, it's a small fracture at the back of the thumb. It's really not a serious injury in that respect but you just can't play with it," said coach Eddie O'Sullivan yesterday when explaining the cause of the injury in Murrayfield was not known.

"It's one of those injuries that when your adrenaline is flowing you probably don't notice it until afterwards."

Into the breach, for country as well as province, steps Mick O'Driscoll.

After eight appearances as a replacement, he will make his first Test start against Italy in Rome's Stadio Flaminio on Saturday, and in the continuing absence of Malcolm O'Kelly, Leinster's Trevor Hogan, hitherto confined to two appearances as a replacement in the Japanese tour of 2005, will be on the bench.

The selection of O'Driscoll ahead of Hogan was well flagged but the continuing omission of Leo Cullen is a puzzle given the homeward-bound lock has been a pillar of the Leicester Tigers' pack this season. He won the last of his 18 caps in the autumn of 2005 against Romania.

"He's still in the squad, but he's behind the current line-up," was all O'Sullivan would say of Cullen. "At the moment he's probably just behind Trevor."

Meanwhile the out-of-favour Bob Casey remains off the radar altogether.

Palpably out of position in the Munster back row in January against Bourgoin and Leicester, O'Driscoll hasn't had a run of games at lock this season, but presumably his off-colour display for Munster in their recent home defeat to Cardiff was a blip and his first Test start will bring the best out of him.

The 56-times capped Simon Easterby has captained Ireland and will presumably take over as pack leader, with the responsibility for leading from the front resting more heavily on Donncha O'Callaghan.

The only other potential change to the team that struggled to eventually subdue Scotland 19-18 last Saturday could see the return of Marcus Horan, pending ongoing assessment of his troublesome calf, in which case Simon Best would revert to the bench. But the twice-capped Bryan Young, who was on the bench last Saturday, will travel to Rome.

"It'll be tight," commented O'Sullivan, who said a decision would be made by Friday.

The damage from last Saturday could have been worse, mind, given Brian O'Driscoll concurred with O'Sullivan's assessment that but for the operation by Dr Jimmy Corville post-Lions 2005 he might well have dislocated his shoulder again when falling heavily in Murrayfield.

O'Driscoll did take a full part in what O'Sullivan said was yesterday's first of only two 80-minute training sessions this week: "They're battle-hardened enough now. We need a big performance on Saturday and there's no point in burning guys out. They're fresh and enthusiastic but I want to keep that freshness there."

Reviewing the Murrayfield game confirmed his impression that an inability to convert line breaks and ill-discipline were their primary problems. Five line breaks - their own stats showed 15 in total - in the first quarter yielded only three points.

"That's a killer," he said, "and the other small thing we didn't do was firewall our ruck ball, protecting static ruck ball, and (hence) it wasn't as clean as we would have liked for Peter (Stringer)."

Most likely Ireland's failure to build up the kind of winning margin they were capable of has put the title out of reach. Ireland must have at least a five-point bigger winning margin on Saturday than France, who host Scotland later that afternoon.

Though disadvantaged by the staggered kick-offs, O'Sullivan acknowledged: "In the modern game you can't put three Test games on at the same time. It would be ludicrous. People want to watch the three games and they're entitled to see them live."

Needless to say, Ireland will not be unduly mindful of points differential.

"Rugby is not a game you go into with an expectation of racking up scores and the most important thing on Saturday is to win," said O'Sullivan. "If we get a result then we're in the championship still."

Almost inevitably, there was another airing of the alleged choking of Ronan O'Gara in the final play of the Scotland game.

O'Sullivan dismissed as "nonsense" the claim by the former Scottish player David Sole that the Irish coach was creating a smokescreen to cover the fact O'Gara had sustained concussion.

"Is he a doctor?" O'Sullivan asked sarcastically, before asserting, "Our medical staff are 100 per cent in unison that Ronan O'Gara didn't have concussion of any description, did not swallow his tongue and did not have blue paint on his face."

He did not regret his post-match claims a Scottish player had attempted to choke the outhalf but confirmed he and his Scottish counterpart, Frank Hadden, had attempted to contact each other, without success, on several occasions.

Accepting the whole imbroglio has portrayed the sport in an unfavourable light, O'Sullivan said: "Every so often in rugby something happens that everybody's not happy about but you gotta move on. We can't cancel everything. It happens in all sports I think at some point. Everyone's had a say about it and we all want to look forward to Rome. It's pointless going round in circles."