Claude Puel has spent the past fortnight with his focus on one game and one game only.

Whirring through his mind will have been all the potential options at his disposal as he aims to defeat Manchester United to win the EFL Cup for Saints.

Puel had the luxury of giving his players four days off to freshen up, before a training camp in Spain and then a few days back home to finish off preparations.

In the meantime, United have played three matches.

Whether the freshness of Saints or the match sharpness of United will make any kind of difference is very hard to assess.

However, what is for sure is that the decisions made by Puel and United counterpart Jose Mourinho will play a significant factor in how the game plays out.

Here at the Daily Echo, we take a look at some of the issues Puel has been contemplating as he decides on his all-important team selection for Wembley.

Formation

Puel has been steadfast in his approach – right up until the last game.

Despite the majority of the current squad having been used to a 4-2-3-1 over three very successful seasons, Puel had his own ideas on taking over and implemented the diamond midfield.

He did adapt things slightly after a poor start, but the evolution over the course of the season has more come in terms of minor tinkering rather than wholesale change.

There was great surprise, therefore, that he made a drastic switch for the game at Sunderland, going to the 4-2-3-1.

It worked a treat as well.

Saints looked so much more comfortable, they were solid, the full backs more effective and Dusan Tadic utilised well in the hole behind Manolo Gabbiadini.

Now Puel has the dilemma of whether to stick with it for Wembley.

It does give Saints a slight potential element of surprise, but Mourinho has options too.

Take United’s last three league games, and they have played a 4-2-3-1, a 4-4-2 and a variation of a 4-3-3.

How the managers decide to go could have a big impact on the game.

To change a winning team?

Puel has become known for his team changes, having not named the same side twice in a row since taking charge.

Of course, much that has been a very deliberate rotation policy he has implemented in the belief it will help his squad manage the workload of a very hectic season that includes European football.

He has already hinted that rotation is at an end as Saints hit a more normal period of fixtures.

You would assume, therefore, that includes keeping players in the team who are on form, and leaving out those who are not, which has not necessarily been the case when rotation has been used.

Changing a team that has just won 4-0 would be a major gamble.

Puel has not been afraid to make changes in the past but maybe, just maybe, this could be the first time he names an unchanged side?

Centre halves

Wind back just a couple of months and you would have confidently said that Jose Fonte and Virgil van Dijk were Puel’s first choice centre half pairing.

Going into the game at Wembley he has neither at his disposal.

Fonte’s departure has been well documented, while van Dijk’s injury means he is unlikely to play again this season.

Saints have brought in Martin Caceres as another option with Jack Stephens and Maya Yoshida having taken over central defensive duties, with Florin Gardos as a back-up Puel appears reluctant to use.

Naming Caceres in the side would be a colossal call from Puel. He hasn’t played in over a year and has only had just over a week with his new team.

To give him a debut would not only be the mother of all gambles, but also risks a rift.

Yoshida and Stephens will feel with some justification that they have earned the chance to play at Wembley, having been so strong in the semi against Liverpool.

If either of them is left out then there is bound to be resentment, while dropping Stephens for a player who has only just arrived would really blow apart the idea Saints are keen to trumpet that they promote youth and do not just bring in short term foreign imports on big money to plug a gap.

Is that wrong to win a one-off game? And when you have Ibrahimovic to deal with?

Puel has a lot to think about.

Style

The way in which Saints play, the so-called entertainment factor, has been a huge talking point this season.

Fans have been frustrated by performances in some matches, particularly at home, which have not always been the most thrilling affairs.

This game is all about winning.

Puel will know that no one will remember the performance from a cup final, but the result lives forever.

Manchester United are not known for their expansive football under Mourinho, and so it could be a relatively cagey match with both teams keen to keep things tight at the back and not overcommit going forward.

It is hard to imagine Puel playing anything other than a possession based counter attacking type of game.

Subs

There are going to be a few disappointed players in the Saints squad.

Some, including potentially Shane Long, will feel hard done by if a decent run of form doesn’t get them a starting place.

Others will not make it into the matchday squad for a chance to play at all.

Puel will have to load his bench up with a careful balance.

He will want to have cover for his defence and midfield, but is more likely to fill three or four spots with attacking talent should his side need a goal.

He won’t want to be caught short on the big day.