Danny Shittu's short-term deal with Millwall runs out soon, prompting English Championship rivals Cardiff City to reveal their interest.
The Nigerian centre-half joined the Lions in October after leaving Bolton and has started nine league games since arriving at The New Den but he may be again on his way if Cardiff get what they are looking for.
City boss Dave Jones is keen to strengthen his squad, which currently sits third on the league table, and wants Shittu in January.