The Spain striker has currently passed a healthcare and Chelsea have satisfied the 32m buyout clause in his contract.
Costa has also directed Atletico to settle for the offer and Sky sources recognize that Chelsea are established to get the offer done in advance of the commence of the Planet Cup, so that he can focus on the tournament.
"Chelsea have manufactured an present to Atletico Madrid in compliance with the buyout terms in Diego Costa's deal, and have been encouraged that the player has presented recognize to Atletico Madrid invoking the buyout clause and directing the club to acknowledge Chelsea's offer," explained a club source.
"Chelsea seem forward to coming into into formal transfer documentation with Atletico Madrid as soon as feasible so that the player can concentrate on the Globe Cup."
The Brazil-born ahead scored 36 ambitions in fifty two online games final season as he helped Atletico win the La Liga title for the initial time because 1996 and reach the final of the Champions League.
Costa limped off after just nine minutes of the final in Lisbon which was received by metropolis rivals Actual but the twenty five - 12 months aged is healthy all over again and instruction with Spain ahead of the match in Brazil.