Just like players, most managers take time to accustom themselves to the international stage. Mick McCarthy has conceded more than once over the past few months that his own elevation may have come a little too early for him to make the step up entirely smoothly. But at Lansdowne Road this evening he and the players he has gradually moulded into one of Europe's most consistent sides have the opportunity to prove beyond doubt that the learning process has been completed.
Seven of the team that will start against Iran today made their senior debuts during the five and a half years of the McCarthy era. During his tenure to date we have seen the evolution of a side that is almost certainly now the equal of any put together by Jack Charlton. Indeed, over the past two years, they have surpassed anything achieved by those guided by McCarthy's predecessor during his five qualification campaigns.
In the circumstances, it seems almost unthinkable that what has to date been a heroic effort to qualify for next summer's World Cup finals in Japan and South Korea might be thwarted by another play-off defeat. McCarthy is understandably cautious about his team's prospects. On both of the previous occasions that his sides reached this point, they received favourable draws in the play-offs and still, having been unable to win at home, failed to qualify.
What is different this time, though, is that on the one hand both he and his team have matured and developed into their roles and on the other they have drawn opponents who, though well organised and possessing a sprinkling of talented players, are far more flawed than either the Belgians or Turks.
Many regular and favourably-disposed observers of Iran argue that the recent games against the UAE should be disregarded when attempting to assess the team's strengths and weaknesses. The theory is that this weekend's visitors to Dublin raise their game against better opposition.
But the reality is that McCarthy will have found it difficult to come away from the Asian play-off games without a growing sense that the Republic finally have qualification for a major championships entirely within their grasp. Miroslav Blazevic's side are undoubtedly capable of causing difficulties for Ireland over the next five days. But while they are threatening from set-pieces and boast individually-talented players in Ali Daei, Ali Karimi and Karim Bagheri, Ireland's players have done enough over the past couple of years to suggest that they can comfortably cope with the challenge.
That McCarthy has remained loyal to the players who have performed so strongly for him in recent months is scarcely a surprise. Telling Mark Kinsella, Gary Kelly and Richard Dunne that they were not playing was very difficult, he said yesterday, but not so hard as dropping Steve Finnan, Gary Breen and Matt Holland would have been after the Holland and Cyprus games.
If the form of those two games can be reproduced this evening, then Iran are in for a rough time. Their more skillful ball players, Karimi and Bagheri, are unlikely to relish going face to face with Roy Keane and Holland, while a defence that looked ragged when they attempted to defend a lead against part-timers early on in Abu Dhabi will surely find the going much harder when confronted with strikers of a higher calibre.
Keane's performance, of course, will once again be pivotal, but the relentless drive that he has demonstrated to date in this campaign suggests he will defy the ongoing knee injury he admits might well require a great deal more attention after these games.
Yesterday, he said that this group of players not only deserves to go to the World Cup but also needs to if they are to progress and further their development.
A good win would almost certainly put the tie beyond Iran. They will most likely be improved by the return of Mehdi Mahdavikia and will almost certainly come to defend in the hope of taking a nicely-balanced tie back to the intimidating setting of their vast Azadi stadium next week.
But if Steve Staunton and Gary Breen can maintain the sort of central defensive showings that have led to Ireland conceding just five goals in their previous 10 World Cup games, and the midfield battle is - as it should be - won comfortably, then there will be a tremendously firm foundation to build on.
On the flanks, there are defensive weaknesses for Jason McAteer and Kevin Kilbane to expose if they play well, while around their own area Iran can look terribly shakey. In their current form, both Niall Quinn and Robbie Keane have the ability to profit handsomely if things start to go wrong for the visitors, while the bigger man's replacement later on with a more agile and pacey player has the potential to bring Blazevic's three-man defence a whole new set of problems.
Things, of course, can always unravel and the Iranians are not incapable of capitalising back in Tehran if they emerge today with anything on which they might build. Nothing in this Irish team's recent history, however, suggests that they will.
McCarthy's men have surely come too far together to get stage fright now. Rep of Ireland v Iran: Lansdowne Road, 6.0
IRELAND: Given (Newcastle United); Finnan (Fulham), Breen (Coventry City), Staunton (Aston Villa), Harte (Leeds United); McAteer (Sunderland), Holland (Ipswich Town), Keane (Manchester United), Kilbane (Sunderland); Quinn (Sunderland), Keane (Leeds United).
IRAN (possible): Mirzapour (Foolad); Peyravani (Pirouzi), Golmohammadi (Foolad),Rezaei (Perugia); Mahdavikia (SV Hamburg, Germany), Bagheri (Unattached), Kavianpour (Pirouzi), Karimi (Al Ahli, UAE), Minavand (Sturm Graz, Austria); Daei (Hertha Berlin), Vahedinikbakht (Esteghlal).