Chelsea and Atletico Madrid have reached an agreement for the transfer of Diego Costa, the two clubs confirmed on Thursday.
"Atletico Madrid and Chelsea have reached an initial agreement for the transfer of Diego Costa," the Spanish club said in a statement.
"The agreement is pending the formalisation of the contract between our club and the Spanish international forward.
"The English club has authorised Diego Costa to travel to Madrid in the coming days to undergo medical tests and settle his contract with our club."
Marca say talks on "Wednesday night into Thursday morning" yielded an agreement between the two clubs over a deal for the Spain international striker.
The final details still need to be finalised but there's no rush as Costa cannot play for Atletico until 2018, due to the transfer ban they have been serving.
According to Marca, Atletico will pay around 60 million euros for the Brazilian-born forward, which includes the variable.
Meanwhile, AS say that Costa will undergo a medical in Madrid in the coming hours ahead of a 55 million euro move, plus 10 million euros more in add-ons.
Costa will sign a three-and-a-half year deal, keeping him at the club until 2021.
Atletico have already signed former Sevilla player Vitolo, who will join them in January, too. He is currently playing for Las Palmas.