Southampton are interested in signing the Real Valladolid centre-back Mohammed Salisu.
The Saints are among a number of clubs to have scouted the 20-year-old Ghanaian this season, and his £10.2m (€12m) buyout clause makes him an attractive prospect.
However, Southampton are prioritising new signings at both full-back positions in January, with plenty of options in the middle and a resurgence in form.
Sky Sports News has already reported that Genk's Joakim Maehle is one name on their right-back list, but a loan move for Tottenham's Kyle Walker-Peters to St Mary's has been described as "unlikely".
At centre-back, Southampton also have an interest in Red Bull Salzburg defender Marin Pongracic.
Other clubs in Germany, Italy and Spain are also keen on Salisu, who has two-and-a-half years left to run on his contract and has impressed across 18 appearances this season.
How to follow the January transfer window
Sky Sports will bring you the very latest news from the January transfer market with the return of three shows.
Start your day with Good Morning Transfers at 9am as our team of reporters bring you the latest news and insight. Transfer Talk then follows at midday delivering analysis of the biggest stories. Then join us at 7pm for the definitive round-up of the day's news with The Transfer Show.
The Transfer Talk podcast will also be back with more expert analysis from here and across the continent.
And as well as tuning into Sky Sports News, don't miss a thing with our dedicated Transfer Centre blog.