Costa has not appeared for the London club this campaign and spent much of August in his native Brazil. He was told by text message that he was not in Antonio Conte’s plans for this season.
The striker stated this summer his wish to return to Atletico, and said Chelsea were treating him like “a criminal” by demanding an “impossible fee”.
His position in the team had also been placed under threat by the arrival of striker Alvaro Morata from Real Madrid during the last transfer window.
Problems between Costa and Chelsea surfaced earlier in the year when he was left out of the Chelsea side for an away match at Leicester having been involved in a dispute with a fitness coach.
This followed reports of an offer from China that would have been worth £30m a year in salary. At the time, Chelsea said they had no intention of selling him.
Later in that month, Tianjin Quanjian’s owner said a bid to sign Costa had been scuppered by new rules over foreign players in the Chinese Super League.
You couldn’t really see a way back for Diego Costa. It’s a shame in many ways because if Chelsea had kept him on-side until January, can you imagine the team they would have?
To some point Antonio Conte will be breathing a sigh of relief because things had got ugly.
How strange that this happens the day after Michy Batshuayi scores a hat-trick.