Last season Southampton finished with the second strongest defence, in terms of goals conceded, in the Premier League.
Only champions Chelsea had a stronger defence.
However, with Toby Alderweireld moving to Spurs and Florin Gardos out injured for 'six to seven months', who will Ronald Koeman sign to strengthen a squad with only two senior center-backs?
The ideal signing: Virgil Van Dijk
The 6'3'' Celtic defender is in high demand at the moment with clubs such as Everton, Manchester United and Southampton reportedly monitoring Van Dijk's situation.
The Celtic defender has recently stated in a interview that 'a move to the Premier League would help (his career)' and later mentioned that if Celtic did not advance in the Champions League he would move away from Celtic Park.
Sources, however, are reporting that Everton are in pole position after tabling a £10 million bid, which may open the door for Stones's move to Chelsea.
The cheap option: Ron Vlaar
Another Dutch defender could be making his way to the Saints his summer, despite his recent injury, which means he will be out for the first three months of the season.
Despite this Ronald Koeman may take a risk and hope that neither Yoshida nor Fonte get injured and that Jack Stephens can make the step up to the first team.
Last season Vlaar was in demand with Manchester United and Saints showing an interest in the experienced center-back. Available on a free transfer Koeman could even sign another defender to add eve more depth.
Heavily linked player: Steven Caulker
Virgil Van Dijk and Vlaar have been heavily linked but more recently Steven Caulker, of QPR has been linked with an £8 million move to the south coast club.
The 23-year-old former England international was one of the shining lights of QPR's season last year and the young defender has plenty of time to develop in the future.
On top of this Caulker would be available on loan, which allows the Saints to make a bigger risk on Caulker. A future of fee £8 million may be part of the loan deal.
James Chester: The Hull defender is poised for a move to West Brom but the Saints, having been linked with the ex-Manchester United player, may make a last minute bid for around £8 million.
Terence Kongolo: The 21-year-old Feyenoord defender made his debut under Koeman and has already made 2 appearances for Holland and has been linked with a move to Chelsea and Southampton but a price tag for the player is unknown.
Sven Van Beck: Yet another Dutch defender once made his debut under Koeman at Feyenoord and has appeared for the Netherlands Under-21's but, due to his lack of experience, could be a bit of a wild card for the Saints.