Atletico Madrid have offered £22m ($28m) plus add-ons for wantaway Chelsea striker Diego Costa, according to reports.
The Daily Mirror says Atletico are confident of re-signing Costa in the current transfer window despite a transfer ban rendering them incapable of registering new players until January.
The La Liga side are reported to have drawn up a special training programme to keep Costa match fit while he is not playing games.
Atletico boss Diego Simeone is determined to bring Costa back to the Spanish capital, while Chelsea are also open to the possibility of selling him.
Blues manager Antonio Conte informed Costa via text message that he was no longer part of his plans last month, with the club's hierarchy fearing that the move wiped out millions off the striker's market value.
The Daily Mail reported over the weekend that Atletico had shelved a plan to loan him to a club in China or Brazil if they do manage to sign Costa and will have him train with their squad until he can play again in January.
Costa admitted last month that he was interested in rejoining Atletico but expressed concern over potentially missing five months of football ahead of the 2018 World Cup in Russia.
"Conte has sent a message saying that he does not want me. If they don't want me there, I'll have to search for a team," Costa was reported as saying by the Daily Mirror.
"To go to Atleti would be nice but I have to think about it. This is a World Cup year and I cannot be not playing for three or four months."
Chelsea have made it clear to Costa that he will not be permitted to negotiate his own exit from Stamford Bridge, given the fact that the Spain international still has two years left on his contract.
Costa's representatives are due to hold talks with Chelsea officials later this week, with the player set to return from holiday next week.