Chelsea had expected the striker to return to London and make himself available for selection if the striker is to seal a move back to Atletico.
But the 28-year-old has not reported for training, having previously claimed that the club has made him feel like a 'criminal'. Costa has now reaffirmed that stance.
“My destination is already made. I must return to Atletico Madrid," a statement released by Costa read.
“It turns out that there is the impasse that Chelsea does not want to release me.
“But I believe that this situation will be resolved now on my return to Spain."