Atletico Madrid have reportedly contacted Chelsea over defender Toby Alderweireld.
Reports have suggested that the Premier League champions are interested in signing the 26-year-old, who spent last season on loan at Southampton.
It is thought that Ronald Koeman's Saints retain an option to purchase the Belgian international for close to £7m, but Madrid can halt those plans by paying a £1.5m fee to remove the clause.
According to Get West London, Atletico have offered Alderweireld to Jose Mourinho's side and are monitoring the situation of Blues full-back Felipe Luis.
Luis joined Chelsea from Atletico last summer but has been linked with a move back after failing to hold down a starting place at Stamford Bridge.
Alderweireld played 28 times for Southampton last term.