Ian Dennis in Las Palmas
BBC 5 Live commentator
Realistically, Northern Ireland should have no chance of qualifying for the Euro 2008 finals but with this campaign, it's a case of expect the unexpected.
Nigel Worthington's side beat Denmark in Belfast on Saturday
It's impossible to predict anything in this group. All predictions and logic have gone by the wayside and the formbook has gone out the window. There has been no rhyme or reason to most of the results.
Northern Ireland have beaten Spain, Sweden and Denmark but two defeats by Iceland and one by Latvia could ultimately cost them.
Spain have only lost four of their last 74 qualifying games at home or away and Northern Ireland have only won two of their last 28 away qualifiers but something in the back of your mind says they could still win in Las Palmas.
You can throw all the statistics in the world at this group and it means nothing.
It has been a real rollercoaster ride and you couldn't have written a script for the sequence of results and if you had, you wouldn't know what the last chapter would be.
One thing is for sure. There is a real sense of belief among the players that they can still beat Spain and qualify.
They may be facing a world class side away from home but they are going to give it a real go and don't want to let the 4000 travelling fans down.
They have nothing to lose and Sweden will be feeling a bit jittery, having wasted two chances to qualify.
They could have booked their ticket to Austria and Switzerland by beating Northern Ireland at home or Spain away but by all accounts they were awful in Madrid on Saturday night.
The Green and White Army has been filing into Las Palmas since the weekend and the atmosphere is great out here
Although they have not lost a competitive game at home for three years, they are going to be feeling the pressure.
Nigel Worthington has a few selection posers to consider and although Kyle Lafferty is back from suspension, it would be very, very harsh to drop Warren Feeney.
He scored with a good header against Denmark, led the line well and could have had a hat-trick.
If anything, he is slightly more experienced than Lafferty and although he is suffering from a slight knee problem, wild horses wouldn't stop him playing in this game. Every player wants to play in this one.
Keith Gillespie will be missing through suspension and that's a blow as you want your experienced players on the pitch for a match like this.
I know Keith was disappointed the referee didn't take the conditions into account when booking him on Saturday and that was his fourth yellow card in nine games. Ivan Sproule is likely to come in and he didn't let anyone down in Sweden.
I think Tony Capaldi will come in at left-back for Jonny Evans, who is also suspended, although Chris Baird is an option.
The manager was desperate to get George McCartney out here as he would have been the natural replacement and I know George was disappointed that he couldn't join the squad.
The Green and White Army has been filing into Las Palmas since the weekend and the atmosphere is great out here.
The progression since the last Euro qualifiers, when they failed to win a game or score a goal, has been phenomenal
This is the biggest following Northern Ireland have had outside the UK and anyone who thought they would come here for a quiet holiday in the sun late in the year will be disappointed as it's a sea of green and white.
The fans seem to want Nigel Worthington to stay and the players want him to stay.
The IFA has been suitably impressed by the second-half display against Iceland, the draw in Sweden and the win over Denmark so the job is his for the World Cup qualifiers - if he wants it.
There will not be any talks until this game is over but it's in the IFA's interest to secure a commitment as soon as possible as they will have to look elsewhere if Nigel does not stay.
I think he has kept an open mind and would like to return to club management at some stage after what he did at Norwich and Leicester but he'll probably let the dust settle for a while after the Spain game.
If Northern Ireland don't qualify, there will be a level of disappointment as expecations have been raised but when people have time to sit back and reflect, I think they will appreciate how far they have come.
If you had said at the start of the campaign that the boys in green would still have a chance to qualify with a win in Spain, albeit with a bit of help from elsewhere, you'd have taken it.
The progression since the last Euro qualifiers, when they failed to win a game or score a goal, has been phenomenal.
Third place in the group is now guaranteed and there is the possibility that they could be in Pot Three for the World Cup qualifying draw on Sunday so Northern Ireland are certainly no longer the laughing stock of European football.
Keith Gillespie and Maik Taylor have indicated they have no plans to retire from international football and their experience will be useful to help a relatively young squad for the next campaign.
After what they have done in this series, nobody will be looking forward to the prospect of playing Northern Ireland in the World Cup qualifiers.