Chelsea striker who scored 22 goals for the Blues this season before being reportedly told via text by manager Antonio Conte that he was no longer in his plans, is still contracted to the Premier League champions for two years.
While there is interest from China, Costa is also reportedly being chased by AC Milan after a move back to Atletico Madrid was all but ruled out as a result of the club's transfer ban.
Costa, who scored as Spain beat Macedonia 2-1 in a World Cup qualifier on Sunday, told reporters after the game: "I have a contract with Chelsea, they have to know what to do with me and I have to wait and know the decision that my club takes.
"I have a contract of two years with Chelsea, they have to decide. If they sell me, I will look for the best choice."
On an Atletico return he said: "Atletico is among them, it would not mean not playing, they can loan me out to some team in Spain, Brazil or wherever, but I have to play.
"Everyone knows that I have a lot of affection for them. Of course I rule out China, I have to think about the World Cup. Atletico is a club that I have a lot of affection for, independently of whether I go there or not, I will continue to love them."
And when quizzed about his relationship with Conte, he added; "In life there are good and bad people. I'll stay with the good of everything. You have to ask him, not me. It's an opinion of the coach, if he has the option of putting another in.
"But there are things and ways of doing things and saying them. But well, thanks to God I do not lack teams."