ROY KEANE remains at the heart of selection speculation in the countdown to the Republic of Ireland's World Cup meeting with Iceland at Lansdowne Road tomorrow.

In keeping with his declared policy, Mick" McCarthy is still not prepared to go public about his plans for the Manchester United player in a team selection which may now be delayed until just before kick off.

That Keane will play is scarcely at issue. The bigger question by far is where McCarthy chooses to deploy him as he prepares to rehabilitate the player who snubbed him and, by extension, the football public when ignoring an invitation to captain the national team during the US Cup in June.

The options include slotting him into the central midfield role which was his almost by right during the second half of Jack. Charlton's reign or assigning him the defensive vacancy occasioned by the absence of Steve Staunton.

If this latter posting would represent a first for him in international football, he has operated in central defence on occasions for Manchester United in the course of his varied and colourful career at Old Trafford.

There are those who believe that in a game in which the emphasis will be on attack, McCarthy cannot afford to sacrifice the aggressive running which has established Keane amongst the best midfielders in Europe.

The counter argument is that it would enable McCarthy to leave intact the midfield trio of Jason McAteer, Andy Townsend and Alan McLoughlin who represented the power base of the team in the 3-0 defeat of FYR Macedonia.

Either way, it threatens to be a difficult decision for the manager, governed by the over riding consideration of getting Keane back into the team at the first opportunity after his controversial eight month absence from the squad.

"It's a problem but a problem which many managers would gladly have," said McCarthy. "I have no doubt that if Roy were asked to play at the back he would do a thoroughly professional job there.

"And I also have to take into consideration the fact that a lot of the credit for our recent performances goes to the fluency and rhythm we've developed in midfield.

"This was where it all started for us in the Macedonian game and I've got to think long and hard before arriving at any decision to break it up."

On the risk of minimising Keane's impact if he plays him at the back, he said: "Good players are never more dangerous than when breaking from the back. This is the job Matthias Sammer did for Germany in the European championship finals in the summer and nobody can tell me that Sammer is a better footballer than Roy Keane."

Among those monitoring the situation will be Liverpool's Phil Babb, dropped for the first two games in the competition but for a recall if the option of playing Keane in defence is rejected.

The other selection question awaiting answer is McCarthy's choice of a frontline partner for Tony Cascarino who, in the wake of Niall Quinn's latest misfortune, now looks certain to play an influential part in the qualifying programme.

There was a time when John Aldridge's claims were irresistible after he had recovered from an uncertain start to his international career to close within a goal of Frank Stapleton's Ireland record of 20.

Now 38, the fact that he chose to leave himself out of Tranmere's starting line up for their last two games is a point which will be analysed by McCarthy.

Unlike Aldridge, David Kelly marked his arrival in the team with a spate of goals but then drifted, undeniably, into the role of a fringe player whose appearances in the team were largely restricted to non competitive games.

However, his chances are enhanced by the fact that he has been playing regularly for Sunderland and doing well enough to meet with the critical approval of his manager Peter Reid.

After the consummate manner in which" Ireland dismissed the challenges of Liechtenstein and Macedonia, there is a disturbing climate of complacency which suggests that the only point at issue is the margin of the home team's win.

That is not a view shared by either McCarthy or his players and it ignores the hazards of history. If Iceland have yet to beat the Irish, they have gone sufficiently close on occasions to prove that they are always deserving of respect.

That said, it will require an enormous exercise in motivation by their manager, Olaf Olafsson, to inspire them to such heroics after a crushing 4-0 defeat at home to Romania last month.

Additionally, he must now plan from depleted forward resources following, the withdrawal of the Gunnlaugsson twins, Bjarki and Arnar, and Arnor Gudjohnsen, who scored their only goal in the competition to date, in the 1-1 home draw against Macedonia. Bolton's experienced defender, Gudnif Bergsson, is also very doubtful.

He can, however, call on mature defender Olafur Thordarson, who has 71 caps, and he could prove influential in a game in which the visitors are likely to be required toe absorb a lot of early pressure.

With treacherous away assignments in Macedonia and Romania still to come, McCarthy cannot afford to settle for less than three points tomorrow.

The challenge facing McCarthy is clear. In ensuring that the cover for goalkeeper Alan Kelly is never less than adequate, he must still require players to push forward in the task of opening up what is likely to be a heavily massed Icelandic defence.

That imposes added responsibilities on players like Townsend, McAteer, McLoughlin and, perhaps, Keane. Their response should ensure that the Republic go into 1997 with maximum points.