Giovanni Trapattoni has worked in football for decades and has built a hugely successful career. But after a dreary loss to Croatia in their opening game at Euro 2012, critics are calling for the Republic of Ireland boss to change his tactics. Should Kevin Doyle be dropped? Should James McClean start? The problem for Ireland is that Spain are next up. Here, Sky Sports argues over the debate.
Raz Mirza: Trapattoni needs to change his tactics, because...
When the Republic of Ireland head coach named his side a week in advance of the Croatia game, Slaven Bilic must have been rubbing his hands with sheer excitement.
In their first major tournament appearance in a decade we might have hoped for a bit of action, but the move backfired as Trapattoni's troops looked tired and lethargic.
The warning signs were there six days before the opening game when they were battered in Budapest by Hungary, despite coming away with a goalless draw.
And then complaints of overtraining and fatigue in the camp were largely ignored by the veteran coach as they headed to their base camp in Poland.
This was not the usual high-octane Irish side from the past at big tournaments such as Euro '88 and at the 2002 World Cup, where they would put a fear of God into their opponents with their approach to games.
Trapattoni brought Simon Cox on in the second half and played him out of position on the left wing and he left Sunderland wonder kid James McClean on the bench when they were chasing a goal.
Spartak Moscow winger Aiden McGeady looked tired and jaded.
A lack of fight, spirit and creativity was evident as they conceded three bad goals to the Croatians after being so defensively sound in their previous 14 games having kept 11 clean sheets in the process.
And now they head into the match against world and European champions Spain knowing defeat would see them heading home with their tails between their legs.
Trapattoni likes his 4-4-2 formation, but against Bilic's men, they were made to look ordinary.
The Italian's line-up is rigid and obvious and the 73-year-old needs to be adventurous with his tactics and bring in fresh faces, otherwise they will be leaving through the trap door as quickly as they arrived.
The bulk of the Irish supporters and the media want Jonathan Walters to start up front against Spain, instead of Kevin Doyle.
Even Robbie Keane's selection has been questioned, with the Irish press calling his position in to doubt after a lifeless display against Croatia.
Perhaps Derby midfielder Paul Green could even be considered for selection in a possible five-man midfield.
Former Inter Milan and Bayern Munich boss Trapattoni needs to find a way for his stubborn system to counteract the free-flowing football of the Spanish, who started their game against Italy with six midfielders and no strikers and have not lost a competitive international for two years.
Tom Mallows: Trapattoni needs to stick with his tactics, because....
Trapattoni has not got Ireland where they are today by making knee-jerk reactions. So to do so now would almost certainly signal the death-knell for Ireland's hopes at Euro 2012.
It cannot be denied the defeat against Croatia was a huge blow. In a group also containing Spain and Italy, the match against Slaven Bilic's side represented their best chance of a group victory - on paper at least.
The players were surprisingly sluggish and sloppy against a vibrant Croatia side, who thoroughly deserved their 3-1 victory.
The frustrated supporters have been quick to jump to conclusions with regards to the team selection and who should or should not be included for the next game.
But now is the time for calm heads and a sense of perspective. Remember, this was Ireland's first defeat in 14 games and a performance totally at odds with their displays in qualifying.
There were a number of factors at play in Poznan on Sunday, not least the fact it was Ireland's first match at a major tournament for a decade. They were not the first and certainly will not be the last team to struggle in their opening match at a major finals.
It simply makes no sense to rip up the plan and start again after one setback, especially if you consider the opposition lying in wait.
Does it really make sense for Ireland to abandon their defensive principles, experiment and open up against the world and European champions? Is it wise to pitch James McClean - who has just two caps and has yet to start a competitive international - straight into a match of this magnitude?
If Ireland deploy a more attacking style, they will be carved apart - no question. Their progress to Poland and Ukraine was not built on such expansive tactics.
If they could play like Spain, they would. But Trapattoni is canny enough to know the strengths and limitations of his squad. He cannot pretend they are something they are not, no matter how important the game.
Remember, the Spain match is a 'must not lose' game rather than a 'must win', so Ireland's primary aim is to ensure they keep their hopes alive going into the final match against Italy. That means avoiding defeat against La Roja.
Of course, such tactics are severely hampered when you concede and early goal, just as Ireland did against Croatia on Sunday.
Ireland should be prepared to open up should such an eventuality occur against Spain, just as any side should be ready to alter their tactics according to the match situation.
However, there is no doubt Ireland's best chance of victory - or at least avoiding defeat - is by keeping things tight at the back, frustrating Spain and hoping to nick something on the counter-attack.
After waiting a decade for this opportunity, Trapattoni's men do not want to throw it all away thanks to one hot-headed reaction to a single setback.
What will be the outcome in the match Spain vs Rep of Ireland?
Rep of Ireland