Atleti feel they have made a more than fair offer whilst those in charge at Chelsea do not want to set a precedent of selling a player when he wishes to leave.
When asked about the transfer, club captain Gabi confirmed that both Atletico and Costa himself want a transfer to happen.
"From what I know, Atletico Madrid want to sign him and he wants to join, but of course there is Chelsea in the middle and when you are part of a club you must respect the badge and try and leave in the best way," he explained to the media in a press conference.
Teammate Koke also faced questions from the media with the Spanish international suggesting that should a return to Madrid materialise, Costa will indeed help the team.
"If Costa joins then he will help the team as he always did, we know he is a great player but right now he is a Chelsea player and I cannot tell you anymore," he explained.