The Blues signed the Spain international from the Mattress Makers two summers ago, after he fired them to a shock La Liga title and the 2014 Champions League final.
The 27-year-old has gone on to amass 32 goals in 54 Premier League appearances for the west London club, helping them win the English title during his debut campaign at Stamford Bridge.
But rumours of Costa wanting a return to the Spanish capital have persisted throughout his Chelsea tenure and the latest reports from Mirror Football suggest it could well take place this summer.
Indeed, they claim Atletico have opened talks with Chelsea to re-sign the Brazilian-born forward at a cost of £35million – a slight increase on the fee the Blues paid two years ago.
And it’s claimed Antonio Conte’s side are ready to sanction the deal now that they’ve all-but-signed a direct replacement in Marseille front-man Michy Batshuayi.