Chelsea are refusing to allow Diego Costa to leave for Atletico Madrid until he meets one condition.

Chelsea and Atletico are close to settling on a fee for the firebrand striker of between €45-55m

However, Chelsea will not approve the deal until Costa meets one demand: APOLOGISE.

AS reports Chelsea management are furious with Costa's constant public criticism of the club and manager Antonio Conte while he has remained AWOL.

And they want a public apology from the Spain international for his behaviour before selling him to Atletico.

For their part, Atletico have been urging Costa for the past fortnight to make his peace, but even yesterday he spoke with a local Brazilian outlet slating Conte's coaching and character.