IT will be a case of history revisited when Roy Keane goes back to the Happel Stadium in Vienna tomorrow for Manchester United's crucial European Champions League appointment with Rapid Vienna.

Some 15 months ago, Keane's return to the Republic of Ireland team in this same stadium was heralded as the rallying point for the renewal of their European championship challenge against Austria.

Instead, it became a disastrous evening as the Irishmen got their priorities confused and sank to a 3-1 defeat, which accelerated the collapse of the Jack Charlton regime.

Later, Charlton was to apportion much of the blame to Keane's failure to temper ambition with caution and discharge his basic duty of anchoring the midfield formation.

That challenge is not wholly different to the one which Alex Ferguson's players now face as they set about establishing priorities for this, their most important away assignment in years.

To make certain of going through to the last eight in the competition, they must win - and then depend on professionalism triumphing over passion in Juventus's meeting with Fenerbahce in Turin.

Just how the carry over of seven yellow cards will effect the competitive edge of a Juventus team already assured of qualification remains to be seen. But, for Ferguson and his entourage, it has the effect of concentrating minds.

"There is no point in dwelling on the different permutations at this point - the important thing is that we play well enough to win," he said.

"How we set about doing it is another matter for in this particular game, there is no margin for error. The bottom line is that we simply cannot afford to lose."

Re-enter Keane. Manchester United, on song, are still heavily indebted to the Irishman's aggressive running, a point well illustrated when he opened the way to that successful late charge against Leicester City on Saturday.

That role can only be undertaken, however, at the risk of weakening the outer ring of defence. And as Ireland discovered in Vienna last year, the wages of the ploy misfiring can be ruinous.

Like Charlton, Ferguson will almost certainly urge patience in Keane's sorties from midfield. The pertinent question is whether the response will be any different from a player whose natural instincts occasionally cause him to stray.

In the transition of the decline of Eric Cantona and the development of those of his younger team mates who aspire to the Frenchman's flamboyant role, the Irishman is now more and more the fulcrum of the side.

But he refuses to accept that his will be the critical contribution if United are to achieve to what their supporters would interpret as the fulfilment of destiny and progress to the quarter finals.

"Football is a team game, bigger than any individual and to suggest that a game of this importance comes down to one player is nonsense," he said.

"Our problems this season are down to the fact that we haven't got the old teamwork going, but Vienna will be a good place to put that right.

"What happened when Ireland played there last year doesn't really matter now. It's a different game with different players and, hopefully, a different result."

One thing for certain is that the versatile Irishman will not be asked to undertake the emergency role he filled in central defence for much of the return game against Juventus at Old Trafford last month.

Gary Pallister's return from knee surgery for the Leicester game convinced Ferguson that the gamble of recalling his tall central defender to European competition is justified.

Given that only five weeks has elapsed since Pallister's operation, it was scarcely surprising that the player reported a soreness in his knee after Saturday's game.

Yet, his stabilising influence on those around him is such that Pallister's name is likely to be one of the first on the teamsheet.

Ryan Giggs, replaced in the closing stages against Leicester, is also likely to play, leaving the choice between Ole Solskjaer and Jordi Cruyff as Ferguson's only difficult decision.