There are question marks at Tottenham over the futures of defenders William Gallas and Ledley King.
If Ajax defender Jan Vertonghen arrives, Tottenham's four centre-backs next season will be Vertonghen, Younes Kaboul, Michael Dawson and Stephen Caulker who enjoyed a successful season on loan at Swansea.
King has a year-by-year agreement with Tottenham because of a persistent knee problem and he has yet to be offered a new deal for next season.