Martin geared for win or bust battle with the Italians
O'Neill is man with a plan in Republic's bid for glory
Lille will quickly disappear from the memory unless the Republic of Ireland defy the odds and produce a tournament defining performance this evening.
It rained heavily yesterday, just as it has rained for most of the last month.
The forecast for today is thunderstorms, meaning that the roof on the Stade Pierre-Mauroy has effectively prevented UEFA from having to move games away from a city which is closer to Belgian than French in terms of its personality.
When it rains here, it pours. Martin O'Neill will be hoping that it's not a metaphor for the direction of the Republic of Ireland's Euro 2016 campaign after the gloom of Bordeaux - the 3-0 defeat to Belgium.
Training at the stadium was off the agenda because of concerns about a playing surface that will be replaced on Friday, so his visit consisted of an unimpressed look at the pitch and an animated chat in the dug-out with Roy Keane and Seamus Coleman.
When the match ends, the squad will head straight back to their base in Versailles to either prepare for a trip home or a round of 16 tie.
It's the definition of win or bust and, prior to his brief walk on the drenched turf, O'Neill attended one of those press conferences where he could only really state the obvious about the task at hand.
"The players know what they have to do and they're ready for it," he said.
An attempt to draw a response to Marco Tardelli's criticism of Irish football intelligence was shrugged off by the Ulsterman and coldly dismissed by Coleman.
O'Neill has acknowledged that they have to be sharper in every department if they are to produce an upset.
Both O'Neill and Keane have tried to dismiss the significance of Antonio Conte fielding an understrength side and they were never going to handle that question any other way.
The Chelsea bound manager was adamant that he will be approaching the fixture with the utmost seriousness, pointing out that Italy ruined Norway's Euro 2016 prospects last October when they had already qualified.
"It's not a useless game to us," he asserted. "It's not a dead rubber. It's a fixture we want to win, we want to keep going because winning breeds confidence and self esteem.
"I don't like people saying it's a game for our substitutes. This is a match for those who've played a little less than other players. And we will make decisions which show what the game means to us."
That was interpreted as a hint that he would make fewer than the reported nine switches. Upon questioning, however, he did not rule out that eventuality.
Conte might encounter a different Republic side too, at least in terms of personnel.
O'Neill said at the start of the competition that he would freshen his side with three games in nine days but he only made one change from the 1-1 draw with Sweden to Belgium.
The expectation is that he will mix things up now with some notable casualties. Ciaran Clark and James McCarthy are tipped to lose out and there are even suggestions that John O'Shea is vulnerable.
Wes Hoolahan and Shane Long were taken off in the dying stages of the Belgian reverse, a move which left the impression they were being saved for the decider although he refused to confirm they would both start.
A reversion to the diamond system that worked against Sweden would suit Hoolahan but the expected unavailability of Jonathan Walters complicates that system. O'Neill says he's "very doubtful".
Daryl Murphy or James McClean would have to come in as support for Long.
O'Neill said that the Republic need to be "strong" in the early stages and stay in a contest that might be decided by just one chance.
"We started tentatively against Belgium," said O'Neill.
"We have to start on the front foot rather than the back foot and everything else will fall into place.
"Early in the game, we can get confidence by doing the right things. Getting support to players like Shane Long becomes vital and that's what we would be looking to try and do. But we don't want the game to run away from us early on."
He spoke as though he was anticipating a tense evening and, for the travelling fans, the nail biter would be preferable to a deflating anti-climax.
It will take a monumental effort to make it a night to remember.