Southampton manager Ronald Koeman has expressed his desire to buy on-loan defender Tony Alderweireld on a permanent deal from Atletico Madrid.

The Saints are believed have an option to buy the defender following the completion of his season-long loan deal, but parent club Atletico Madrid might buy out that option according to reports.

Los Rojiblancos are keen to either keep Alderweireld for themselves or sell him to any other interested club for a higher price than the agreed fee between the clubs, understood to be around £7million.

"That situation is more difficult because it's not up to the player, it's up to the club Atletico Madrid," admitted Koeman.

"Of course we would like to keep Toby but that situation is a little bit more difficult."

The 26-year old Belgium international has made 23 league appearances for the Saints during his season-long loan deal.