Ahead of one of the most important matches of his international career,  Ronan O'Gara insists he and his team-mates are fully focused on igniting  Ireland's World Cup when they face France in Friday's Pool D showdown in  Paris.

O'Gara and the team have failed to hit the ground running during the  opening two matches against Namibia and Georgia. Having won widespread  acclaim for a string of stellar performances over the last year, O'Gara  who has had a mediocre tournament to date, needs to rescale those  heights at the Stade de France.

And the 30-year-old insists his competitive fires burn as fiercely as  ever and bristled when it was suggested his recent demeanour on the  pitch had changed.

"It's 100 per cent inaccurate to say I'm struggling," he said "People  may say my body language isn't like normal but that's the opinion of  individuals. There are all kind of rumours going around that I'm  troubled, cranky and there's lots of fighting going on but that's all  rubbish. I care so much about our performance in the team.

"Maybe I'm a little big negative talking to the press but when I get on  the pitch I'm excited, I enjoy it and I realise what people would give  to wear the green number 10 shirt.

"When you see me barking at fellas it doesn't mean anything. That's my  natural competitive game. I never play with a smile on my face. But ask  the forwards, ask the centres - they know me well enough at this stage to see that it's the same person that always is and always will be."

O'Gara enters probably the biggest test of his career without regular  halfback partner Peter Stringer. Ireland's second most capped player was  dropped for only the second time.

A costly interception try against Georgia convinced coach Eddie O'Sullivan it was time to axe Stringer for Wasps rookie Eoin Reddan.

"My view is that sometimes the half-back combination is overplayed," said O'Gara. "It sometimes suits people to talk about us as a pair but essentially it's not like that. I don't think it will be any different.

"On two Lions tours I played with different scrumhalves and gelled quite quickly, so that isn't an issue for me at all. I'd like to be judged on how I perform, not on how well the half-backs perform. Obviously it's up to the individual to get it right.

"I don't look upon it as a risk. Eoin is a good quality player. He's been exceptional for Wasps and deserves his chance."

Ireland's World Cup is entering a critical stage with two decisive Pool D games against France and Argentina remaining. Conceivably they could lose to France yet still qualify for the knockout stages, but they would probably need a maximum five-point haul against the Pumas.

"It's a huge game," added O'Gara. "We're fully aware of what's at stake. Hopefully it's the game that will kick-start our campaign. If it doesn't then the likelihood is we'll be heading home. We owe ourselves a big performance.

"The team has been shook up and a different side that has never played for Ireland will be taking the pitch on Friday. There are no fellas on the team who shouldn't be there. Eddie has the pick of whoever he wants every week.

"If I knew where things were going wrong I'd be happier within myself. Trying to find that out is not easy. Of course the team is hurting because it's been a disappointing few weeks but we can't be too down - there's nothing fatal at the moment. We should be excited by this challenge."