Southampton have agreed a deal with Dutch club Vitesse to sign defender Alexander Buttner.
The left-back is now due to fly to England in order to complete a medical and finalise personal terms.
Vitesse confirmed the 23-year-old defender was the subject of interest from several clubs.
Southampton, who gained promotion to the Premier League after finishing second in the Championship last season, have already bolstered their squad with the signing of Jay Rodriguez from Burnley last month.
The 22-year-old moved to Nigel Adkins' side in a reported £6 million deal.