Paul O'Connell has warned France not to take comfort from Ireland's faltering start to the Six Nations - because they were still in first gear.

A 19-9 victory over Wales saw the Irish negotiate a potentially hazardous opener in Cardiff but despite scoring three tries, the display hardly justified their status as favourites.

France thumped Italy 39-3 to help erase memories of a disastrous autumn and will be far more ruthless than Wales in Sunday's championship debut at Croke Park.

But Lions lock O'Connell insists Ireland will up the ante to face the defending champions.

"It was a winning start against Wales and we'll take it," he said. "It was a disappointing performance but make no mistake about, it was a great result to go to Cardiff and win. We'll take this on now.

"It was three tries to nil. Sure we didn't play outstandingly well but we showed our experience, used our heads and dug in.

"We don't take comfort from the fact we've played badly and won because we're disappointed we didn't perform as well as we can do.

"But we do play France knowing we have another gear. We've already beaten Wales who were massively up for that game."

Ireland will name their team to face France on Wednesday lunchtime but the line-up could change between then and kick-off.

Brian O'Driscoll suffered a hamstring strain against the Welsh but a scan revealed it is not as serious as first thought and he could be ready for Sunday.

A final decision will be made on Saturday with O'Connell on standby to lead the side if the Leinster centre does not recover in time.

O'Driscoll's centre partner Gordon D'Arcy picked up a groin strain against Wales but is expected to be fit, as is Denis Leamy who had an abscess drained.

The abrasive Munster number eight will take a limited part in training this week.

Ireland have not ruled out Peter Stringer from selection, even though the veteran scrum-half has sustained a hairline break to a metacarpal in his right hand.

An assessment of his progress will be made on Friday so he may yet be included in the starting line-up with Ulster's Isaac Boss ready to plug the gap if he fails to make it.

Leinster second row Malcolm O'Kelly has been added to Ireland's squad in preparation for Sunday.

O'Kelly was ruled out of contention against Wales because of a knee injury and his return will put pressure on starting lock Donncha O'Callaghan and Mick O'Driscoll, who was on the bench in Cardiff.

O'Sullivan admits the opening round of Six Nations matches went according to plan but is certain the tournament will produce its traditional shock results.

"The championship is a dogfight. You can win a big game this week and then fall on your face next week," he said.

"The margins are so tight. If a couple of things go pear-shaped then the game will run away with you. That's why it's such a tight tournament.

"Things probably went according to plan this weekend in according to who was supposed to win and who did win. But having said there will be a few surprises in this tournament.

"The team that doesn't believe that will be the victims of one of the surprises."