The Saints have already brought in two new signings this summer in Stuart Armstrong and Mohamed Elyounoussi, but manager Mark Hughes remains keen on more additions.
Southampton sold Virgil van Dijk to Liverpool in January, and whilst Hughes does have the likes of Wesley Hoedt, Maya Yoshida, Jack Stephens and Jan Bednarek at his disposal, another centre back may be wanted.
Now, Sky Sports report that Southampton are in talks with German side Borussia Monchengladbach over a deal for giant defender Jannik Vestergaard as they look to make him signing number three.
It's claimed that talks so far have revolved around the fee for the big defender, who was part of the Denmark squad at this summer's World Cup in Russia.
Vestergaard's height makes him hugely appealing, as at 6ft 7in tall, he possesses rare size, strength and aerial ability, making him an understandably attractive option for Premier League clubs.
Formerly of Brondby, Hoffenheim and Werder Bremen, Vestergaard has impressed in Germany – and he could now head to the Premier League, whether it's with Southampton or West Ham.