Southampton have been in discussions with Celtic over the potential signing of defender Virgil van Dijk, BBC Scotland has learned.
No offer has been made for the former Netherlands Under-21 international, 24, by the Premier League club.
He is one of several Saints targets as they look to sign a central defender before the transfer window closes.
Tottenham Hotspur beat them to the permanent transfer of Belgium cap Toby Alderweireld in July.
The 26-year-old was on loan at St Mary's from Atletico Madrid last season.
Former Celtic defender Jos Hooiveld was released and has joined AIK Stockholm in Sweden, 20-year-old Jordan Turnbull has been loaned again to League One Swindon Town, while Romania centre-back Florin Gardos is out injured for seven months.
Saints have signed Steven Caulker on loan from relegated QPR, but manager Ronald Koeman wants to add more cover in central defence.
In addition to Hooiveld, Southampton have bought midfielder Victor Wanyama and goalkeeper Fraser Forster from Celtic in recent seasons.
There was speculation linking Van Dijk - who joined Celtic for £2.6m from Groningen in 2013 - with a move to the English top flight last summer.
Celtic manager Ronny Deila said he is not interested in selling Van Dijk and insisted the Dutchman would stay while the club are still attempting to qualify for the Champions League group stage.
The Norwegian's side face Swedish champions Malmo in the play-off round, with the first leg on 19 August in Glasgow and the second a week later.
Southampton are in the Europa League play-off round, with their opponents being Midtjylland of Denmark.