Group E | Yokohama
Tue 11 June | 12.30 BST
Live on Radio Five Live
All of the Republic's players have been declared fit for Tuesday's all-important final group game against Saudi Arabia.
The Irish, who need to win by two goals to be certain of a place in the last 16, had their final training session in Chiba on Monday morning.
Afterwards, manager Mick McCarthy said all players were available for selection for the crucial game in the huge Yokohama stadium.
Sunderland midfielder Jason McAteer had been struggling with a knee injury but he has said he is okay now.
On Saturday, Kevin Kilbane limped out of training with an ankle injury but was fit enough to take part in Sunday's work-out.
McCarthy will not name his team until an hour before this defining game.
But Ireland will be sticking to the 4-4-2 formation which has served them so well in qualifying and at these finals.
Sunderland striker Niall Quinn will start on the bench, ready to play his role as an 'impact' substitute if Ireland are finding the goals hard to come by.
"Changing things during a game can throw the opposition," said McCarthy.
"But changing them before a game could throw us more."
McCarthy said he would not be keeping in touch with the other Group E game between Germany and Cameroon.
Injury-doubt Kevin Kilbane did train on Monday
However, he fancies the Germans to beat Cameroon which would mean any sort of victory would be enough for the Republic.
The Irish progressed from the initial group stages in their previous two World Cups under Jack Charlton.
Naturally, McCarthy would like to match that achievement and there is a growing air of anticipation in the Republic camp.
"The players all know what is at stake," said McCarthy.
"They do not go around talking about it but you can sense it.
"Nobody is taking Saudi Arabia lightly or suggesting it is going to be easy."
Meanwhile, the Football Association of Ireland has refuted claims that supporters were on the Republic's team bus for the match against Germany.
A news conference on Saturday was told that Fifa had acted after security checks revealed several people on the bus did not have the proper passes to get into the stadium in Ibaraki.
A Fifa statement said supporters had been with the team.
But FAI general secretary Brendan Menton clarified the position on Monday.
"The people in question were Mick's technical staff plus the chef," said Menton.
"They did not have the necessary stadium accreditation because they do not have any specific duties there."