The key to Saints beating Manchester United at Wembley will be the performance of the central defenders, but what will the pairing be ?
Back in 1976, in the run up to the FA Cup Final the pundits were highlighting the Saints defence as the weak link with the centre especially in the centre where Stuart Pearson tipped to run riot against Jim Steele and Mel Blythe in our centre.
Forward 41 years and the prognosis is still the same, but this time the expected star of the final is Zlatan Ibrahimovic and the villains of the piece in the Saints defence are still to be decided.
Claude Puel has a lot of hard thinking to do ahead of Sunday's game.
The most likely to play is Maya Yoshida, it cannot be denied he has been a great servant to the club and over that time has put in some great games at various times, but it also cannot be denied that he suffers from lapses in concentration that can sometimes cost us dearly.
That is why he has never really established himself as a first team regular since his early days with the club and has spent most of the last four seasons as back up, at times falling down the pecking order behind Cuco Martina.
But he is the most experienced fit defender we "appear" to have so looks certain to play.
So conspiract theories aside and more of that later, it would seem that Claude Puel has a simple choice in the centre of defence, who to play alongside Yoshida.
The man in possession of the shirt in the run up to the final is Jack Stephens , four months ago his career at St Mary's looked to be ending it's course, as he approached his 21st birthday he had a total of one appearance in a Saints shirt to his name and that was only a 3 minute run out at Coventry in the FA Cup back in January 2012.
He had spent a fair time out on loan, but had only really done it at League One Level, a spell at Middlesbrough last season in the Championship ending with him being recalled because he could not get in the team.
An appearance in the League cup in the 1-0 win over Sunderland did nt look to have kick started his opportunities much until the trip to Everton a little over six weeks ago when a defensive crisis encompassing suspension, injury and toy throwing meant he came on out of position at right back.
But even that did not look like it would be the catalyst for a run in the first team, but then came another trio of mishaps, VVD's injury, Fonte's departure and a failure to sign a central defender in the January window all added up to last chance saloon for Saints and Stephens as well.
Even now he has very limited experience, just three Premier League starts plus two as substitute and although he is undoubtedly a decent player on the ball, that isn't enough at this level and his performances have been mixed, however his last one was his best and that gives hope.
But overall the Yoshida/Stephens partnership has not shown much to suggest that it is one that most Premier League teams would be happy with, Yoshida is a good foot soldier, but he is not a leader of men, he does not marshall his back four in the way that VVW or Jose Fonte do or rather did and sadly that is just what Jack Stephens needs at this stage a steadying hand next to him.
But Puel has to decide whether to keep faith with Stephens of throw in new signing Martin Caceres, the dilemma being that although Caceres has all the credentials and under normal circumstances there would be no decision to make, the Uruguayan has not played in a year.
But some would say that although he will lack a bit of match sharpness, presumably he is now fit and that being the case the skill and experience factors outweigh the inexperience of Stephens.
As they say form is temporary, class is permanent, there are those who would say a player of Caceres talent will still be a better bet than the inexperience of Stephens.
Whatever Puel opts for the only thing certain is that we need the two men chosen to go out and play the game of their lives, something that Jim Steele and Me Blythe did in the 1976 final.
Cup finals often throw up unlikely heroes and again another certainty is that we have three of them fighting for the two places available in the centre of defence.
But could Claude Puel spring an even bigger surprise ?
Does he have something up his sleeve that will be a pleasing shock to Saints supporters ?
We are talking Virgil Van Dyke here !
The club have been very coy on the exact extent of Virgil Van Dyke's actual injury and recovery time, when it happened it looked innocuous, indeed he tried to play on for several minutes and although he could run he looked uncomfortable, but no one thought it looked serious.
Recovery time was very much the centre of speculation with Claude Puel very coy about it, initially he suggested a month out, but has said little since, it has now been exactly a month since he limped off against Leicester City.
In that time we have heard little about the extent of the injury or how well Virgil is recovering and we have seen even less of the man himself and this is perhaps the strangest thing of all, usually when a player is injured for a cup final the club and indeed his team mates do their best to keep him involved and not left out, but there has been nothing, no pictures and no interviews.
It is almost as if Claude Puel wants to keep Manchester United and Jose Mourinho guessing.
Puel has form on this type of behaviour, he seems to like to keep the opposition guessing and there has been many times this season when the Frenchman has insinuated that a player will miss the upcoming fixture through injury only to see the said player named in the starting line up a couple of days later.
Also when we went to Liverpool, Puel took a tracksuited up Sofiane Boufal to Anfield despite the fact that he was not fit to play, but the intention was to make Jurgen Klopp unsure of what our line up may be.
Little ruses yes, but sometimes a little ruse gets big results.
So is Claude Puel keeping Virgil Van Dyke under wraps ? is he actually fit to play on Sunday ? certainly a month out would not affect his overall fitness too much and presumably he would have trained.
But there is the rub ! no one is reporting that he has been seen training, you would have thought that if he was on the verge of fitness then perhaps there would be a leak, so either Saints are in complete lock down or as is probably more likely, Van Dijk is still a way off fitness.
But we await with hope and trepidation, one thing is for sure though, the key area in this cup final will be in the centre of our defence, in every other area we can match United, they are not that much a better side than us on our day, but we really do need whoever the central defensive pairing is, to have the game of their lives, emulate their illustrious predecessors and make themselves the headline story in the football press this weekend.