Judgment day for Mick McCarthy and the team he has constructed over the last 21 months, finds a sharp divergence of opinion on the Republic of Ireland's chances of reaching the World Cup finals by surprising Belgium in Brussels this evening.

For many, the loss of a home point and crucially, a home goal in the first instalment of the two-legged play-off at Lansdowne Road a fortnight ago, has effectively, scuttled the voyage to a third consecutive appearance in the finals.

Others see in the plot, the outline of one of those storied occasions when sporting logic goes out the door and Ireland's propensity for beating the odds, again finds expression.

Between those two polarised positions, is the prospect of a fascinating game to play on the emotions of some 38,000 spectators in the King Baudouin Stadium and a television audience, likely to be measured in multiples of millions.

Some of the 9,000 Irish supporters converging on Brussels, will find solace in the fact that it was this day eight years ago, that Jack Charlton's team, captained by McCarthy, secured their place in the 1990 World Cup finals by winning 2-0 in Malta.

It was on this day also in 1995, that the roof crashed in around Charlton on a night of torrential rain in Lisbon and a comprehensive 3-0 defeat by Portugal, set up Ireland for the final indignity of European championship elimination by Holland at Anfield.

History, then, has to be interpreted selectively in the search for a plausible case for Irish survival and a suitable riposte to those bookmakers willing to offer odds of 13 to 2 against a win for the visitors.

To win, Ireland must score at least once whereas Belgium, with that away goal safely banked, will go through on a scoreless draw. A 1-1 draw will mean sudden death extra time and Ireland will qualify on any other draw.

The other pertinent factor is that eight potential first team players are unavailable, for varying reasons, to Belgium's manager, Georges Leekens. Ireland are missing two, the redoubtable Manchester United pair, Roy Keane and Denis Irwin.

That last statistic was quoted with some emphasis by the likable Leekens at his final press conference yesterday when he again strove to shift the burden of favouritism from his players and minimise the perceived gap in class between the teams in the original game at Lansdowne.

"We played a perfect game in Dublin and we cannot afford to let our standards drop at home. If we do, it's possible that the Irish will go through. Remember they scored twice when drawing in their last game in Brussels 11 years ago and if that happens here, we're out. It hasn't escaped our attention that almost all their better performances in the current competition, have been achieved away from home."

The case for survival in Ireland's camp, is built on the premise that the team cannot play as badly as in the first game when the advantage of Irwin's stunning goal after only eight minutes, was soon lost in the uncertainty which crept like a paralysis through the team. That was untypical of Ireland and it has dominated every waking hour of McCarthy's days since.

"We've watched the video of that game and I believe we have identified the areas in which we can improve," he said. "It suits me fine when people say that we've blown it. I believe that we'll win because I know that we have the players to go and win."

Yet again, McCarthy was defensive to a fault in declining to discuss either the make-up of his team or the tactics he will pursue in the challenge of achieving a first ever win over Belgium in World Cup competition. Leekens, by contrast, was again forthcoming to the point where he named 10 definite starters.

The only doubt - and it's a very real one - concerns the inspirational Schalke 04 midfielder, Marc Wilmots. Wilmots, who demanded the grudging admiration of the Irish fans in the manner in which he ran at the home defence in Dublin has, according to Leekens only a "one in 10" chance of recovering from a hamstring injury sustained in training here.

It means that Gert Claessens, scorer of seven goals in just nine championship games for Bruges this season and again on target in his international debut against Wales last month, is now almost certain to be given the job of supporting the two front runners.

If the loss of Wilmots threatens to be substantial, Belgium will surely profit from the return of their Italian based striker, Luis Oliveira, who missed the first leg game because of suspension. Oliveira's pace and power, which have unlocked some of the tightest defences in Italy in his escapades with Fiorentina, will surely ask pertinent questions of Ireland's central defenders, Kenny Cunningham and Ian Harte. And the decision to break Luc Nilis's successful partnership with Michael Goossens, is compelling testimony to Leekens's faith in the player.

In all, there are five changes in the Belgium team with Glen De Boeck taking over as sweeper from the injured Eric Van Meir and Eric Deflandre and Phillippe Van Der Walle both winning recalls for a third international appearance. It is not by any stretch of the imagination, a vastly experienced international team and yet, even the most optimistic Irish supporters acknowledge that it will be a difficult one to break.

Team news is more difficult to happen upon at Ireland's base, several miles outside the city but McCarthy confirms that Ray Houghton has recovered from his heel problem and that Alan and David Kelly are available for duty, presumably as cover.

The speculation is that Steve Staunton will replace Irwin at left back, that Mark Kennedy will be given the opportunity of exorcising the nightmare of his first appearance against Belgium and that Lee Carsley may be assigned the vital anchor role in midfield to prevent the home team pouring through the centre of the defence.

All of that pre-supposes that McCarthy will go with a 4-5-1 formation, a subject he was not prepared to discus at any cost yesterday. Nor is he ready to say whether David Connolly or Tony Cascarino will get the front runner's job if he chooses to go with this system.

Significantly, Cascarino played with the `A' team on at least two occasions in training this week but Connolly proved so successful as a one man strike force in Romania last April, that he could well be named in the starting line-up.

In the regrettable absence of Roy Keane, the roles of Ray Houghton and the team captain, Andy Townsend, two men who may be playing for their short term futures in international football this evening, will be critical.

Belgium: F De Wilde, M Verstraeten, E Delandre, G De Broek, G Vidovic, P Van De Walle, F Van Der Elst, G Claessens, D Boffin, L Nilis, L Oliveira.

Republic Of Ireland (Possible): S Given (Newcastle), J Kenna (Blackburn), K Cunningham (Wimbledon), I Harte (Leeds Utd), S Staunton (Aston Villa), L Carsley (Derby Co), G Kelly (Leeds Utd), R Houghton (Reading), A Townsend (Middlesbrough), M Kennedy (Liverpool), D Connolly (Feyenoord).