Eddie O'Sullivan believes Ireland's passage into the World Cup quarter-finals could hinge on claiming emphatic victories over Namibia and Georgia.

Ireland face the Pool D minnows in their opening two games of the tournament before closing the group stage with pivotal clashes against France and Argentina.

With three Test heavyweights competing for just two places in the quarter-finals, O'Sullivan believes picking up try-scoring bonus points could prove crucial.

"We are mindful that when we play Namibia and Georgia we must win the games and get the bonus points as well," he said. "In our group it's not beyond the realms of possibility that ourselves, France and Argentina could lose a game apiece.

"The pool could be decided on the bonus points we pick up. Some teams can already start planning for their quarter-final game knowing who they will probably play. But in our group we just can't have that attitude because we don't know what way it will go. It's very hard for us just to get out of the pool."

O'Sullivan admits team selection throughout the group campaign will be shaped by the need to ensure his players are the peak of their powers for the crunch matches against the Pumas and French.

"We have to plan with the knowledge that the two big games are at the end of the group stage. It would be nice if they were spread out but they're not," he said.

"We want to be fresh but battle-hardened as well. If you don't give guys enough match time they won't have the edge they need to play at the top level.

"We have to make sure people are up and running in the early pool games, so the use of the bench will be important."

Ireland's squad was trimmed to the final 30 for the World Cup yesterday with Shane Horgan's knee ligament injury the only outstanding issue.

But O'Sullivan insists the players handed a ticket to France cannot afford to relax as the battle for places in the starting line-up now begins.

"There is a sense now that the die has been cast. As a group the next step now is the World Cup so we can start to gel and bond more as a group," he said.

"While we had 40-odd guys in the camp and fellas don't know if they're in or out of the squad, it makes for funny dynamics.

"There is a lot of relief now and the guys who have been selected feel their World Cup has started.

"It makes things easier for everybody that the hard decisions are over with now. Now the target for players is getting into the 22 and then the starting 15.

"Four years ago there were guys who were happy just to be named in the squad.

"The difference now is the guys won't be happy unless they're in the 22. It's an important difference. There's still a lot of competition to get on the field."