The Daily Mirror have confirmed the sum Chelsea would require to begin talks to seal the almost definite departure of the striker.
After the Spain international revealed Antonio Conte's intention to let him go, Chelsea will not be allowed to play with his price tag, as it is well known that the club are looking to dispose of the 28-year-old.
The Blues paid around £30 million for Costa, meaning they are set to recoup the money invested in the forward. They will, however, not get as much out of his sale as they would have last summer.