Saints are today aiming to make Virgil van Dijk the most expensive defender in the club’s history while also standing firm to hold on to their key players.

With the transfer window slamming shut this evening, the club are determined to tie up the £11m capture of Celtic’s Dutch central defender Van Dijk.

Saints are understood to have agreed a deal in principle with Celtic, and Van Dijk is expected to be the one remaining signing Ronald Koeman has been craving.

However, they also face a battle to ensure they hang on to key players.

Saints are prepared to stand up to Tottenham in their desire to ensure that Victor Wanyama remains at St Mary’s.

On a transfer deadline day that is expected to see Virgil van Dijk become the most expensive defender in Saints history, the club are bracing themselves for a battle to hold on to Wanyama.

The Kenyan midfielder has made it clear that he wishes to leave Saints before the transfer window slams shut this evening.

Tottenham is his intended destination with former Saints boss Mauricio Pochettino identifying Wanyama as one of his priority targets.

Saints though are prepared to play tough to ensure that Wanyama is not the latest big name out of the St Mary’s exit door.

Ronald Koeman has told Wanyama in no uncertain terms that he will be going nowhere.

He was prepared to leave him out of the squad to face Norwich at the weekend while the saga rumbled on, especially as Wanyama said he was not mentally in a place to play.

However, Koeman has made it clear that he expects Wanyama to be fully committed to the club again when the window slams shut.

Les Reed, who is in charge of transfers at the club, is understood to be backing Koeman’s stance.

He is ready to turn down any formal approach from Spurs, and to rebuff the offers that are expected to arrive today.

As they did last summer with Morgan Schneiderlin, when Tottenham were again the suitors, Saints have drawn a line in the sand for sales.

They are already rebuilding following the departures of Schneiderlin, Nathaniel Clyne and Toby Alderweireld, and know very well they cannot afford to lose more key men, especially with so little time to replace them.

It would seem Wanyama’s only hope of getting out would be to cause such an almighty fuss that public opinion amongst the fans turns so heavily against him he makes his position untenable.

Thus far though he has stopped fractionally short of doing that, instead just telling the club he wants to leave.

With Tottenham highly unlikely to offer top dollar for him – last year they tabled around £12m for Schneiderlin, who this summer went to United for £25m – there is no temptation for Saints to sell.

Wanyama still has the best part of two years on his contract, meaning even if he ended up in a stand-off with Saints over a new deal in the future, he would still retain a sizeable value next summer.

Sadio Mane could also be the subject of a large deadline day bid, if Manchester United decide to follow up their interest in him.

Saints are determined not to allow Mane to leave either.

Though the situation is slightly different with United a massive move for any player and the Old Trafford club normally prepared to pay a big premium to get who they want, it would be a significant blow if he left, and so Saints will hope nothing happens, and will try to rebuff any approach if it does.

Saints are also finally expected to get the Van Dijk deal over the line.

It has been no great secret that they have been trying to tie up a deal for the Dutch centre half for a number of weeks, but have had to fit in with Celtic’s timetable as they tried, and failed, to qualify for the group stages of the Champions League.

The Scottish giants now have replacements in the pipeline and have accepted that they will lose Van Dijk to Saints.

They have dropped their initial valuation of £13m, but Saints will still have to cough up a club record amount for a defender of £11m to seal the deal.

Van Dijk is expected to be confirmed as a Saints player today, and, assuming that no key men leave, that will be the sole piece of significant first team business which Ronald Koeman has wanted completed.

There could be a few more minor moves.

Emmanuel Mayuka has already left the club to join French side Metz, while Gaston Ramirez also appears to have no first team future with the club and has just a year remaining on his contract.

A few young players could also be considered for loan moves to Football League clubs to gain experience.