There is no way of healing the relationship between Costa and manager Antonio Conte, so the Blues are prepared to follow through on the player's exit.
The striker has stated he only wants to return to former club Atletico Madrid, though Chelsea are not willing to be bullied into a cut-price deal. Atletico have offered £22 million for the 28-year-old, while Abramovich wants a figure closer to £60m.
After the agreement between Everton and Manchester United came to light regarding Chelsea target Lukaku, Conte has been forced to look for other options, though he has identified his favourite.
A real blow in the Italian's plans. It will, however, not keep Diego Costa at Stamford Bridge.