Ireland's rematch with Wales following their World Cup defeat by the Welsh will be a cracker, promised Irish coach Declan Kidney.

The 52-year-old, who guided his side to top of their pool at the World Cup, beating Australia on the way, said the Irish needed to fix things that had gone wrong in their 22-10 defeat by Wales in New Zealand.

"We need to exploit the opportunities we had but didn't take in the quarter-final and also tighten up defensively," said Kidney.

"Wales took their opportunities and we didn't.

"Little things will make the difference. It'll be a cracker."

Ireland captain Paul O'Connell, taking over from talismanic centre Brian O'Driscoll after he was ruled out of the tournament, said he expected a highly physical encounter spiced up by the World Cup defeat and also a controversial defeat by Wales in the Six Nations last year.

"There has been a lot of talk about this match and given the World Cup defeat and what happened in last year's Six Nations game (a Mike Phillips try that shouldn't have been allowed in the 19-12 defeat) I expect an incredibly physical game," said the 32-year-old lock, who will win his 83rd cap.

O'Connell, who captained the British and Irish Lions in their series loss to South Africa in 2009, said it helped to raise the morale in the camp that since the defeat in New Zealand the players had enjoyed success with their provinces in the European Cup.

"It's hard to say what actual impact that could have on the game itself," said the Munster great, whose province joined Leinster and Ulster in the last eight while there is only one Welsh club.

"It's good to have confident guys coming into the camp. They've been showing good form but inside the camp you have to start learning new calls and rebuilding relations with players from other provinces.

"It is a different level obviously from the European Cup but the upshot is you have a group of players, who have been playing well and winning important matches when under pressure."

Kidney, the 2009 IRB world coach of the year after guiding Ireland to the Grand Slam, said he had no concerns about Leinster's Fergus McFadden late call-up to the starting XV after Keith Earls had to pull out because his new-born baby girl is ill in hospital.

"Well during training this week Fergus was filling the role as Keith was away, so he knows the moves," said Kidney, who added he believed Earls would be back for next weekend's away clash with France as the baby's condition was improving.

"It's just really a mindset thing for Fergus for him to get his head round the fact that he's starting rather than being on the bench. However, its the kind of call you want to receive rather than the other way round."

O'Connell, who won two Heineken Cups under Kidney when he was Munster coach, said he hadn't paid much attention to the ailments concerning the Welsh camp during the week, which had left coach Warren Gatland no choice but to wait till Friday to announce his team.

"If it had been later in the tournament then one might pay some attention but going into your first game you are really focussed on learning all over again the calls and the moves," he said.

"I always though some would make it and obviously they are delighted to have both Jamie Roberts and Rhys Priestland (both had knee injuries) fit to start as they were pivotal in their World Cup win."