Diego Costa must renege on his promise to remain in Brazil and instead return to Chelsea to have any hope of securing his desired move to Atletico Madrid, Belfast Telegraph Sport understands.
Costa has criticised Chelsea's treatment of him this summer, saying he is "not a criminal" and insisting he is prepared to remain in exile for a year.
But it is understood that Chelsea want Costa, a player with two years remaining on his contract, to return to the club.
The Blues also expect the Brazil-born Spain striker to prove his fitness and make himself available for selection.
After being granted an additional week of leave and missing the pre-season tour to Asia, Costa is still to return to London around two weeks after his anticipated arrival as he agitates for a return to Atletico.
Costa, speaking at his family home in Lagarto, Brazil, said he has not reported for training as he does not want to train with the Blues' reserves, and is happy staying in Brazil and paying club fines until his future is resolved.
He said: "They gave me a week extra off but since then it's fines all the way. They want me training with the reserves. I am not going to do that.
"I am not a criminal and I am not in the wrong here. So, if they need to fine me, let them."
Chelsea do not have a reserve team, only age-group sides, and Costa has been given no indication he would be expected to train with them, Belfast Telegraph Sport understands.
Costa joined Chelsea from Atletico in July 2014 and has twice won the Premier League title.
He has scored 59 goals - 52 in the Premier League - across 120 appearances for the Blues.
The 28-year-old claims he was told he was not wanted by head coach Antonio Conte by text message in the summer and the frontman wishes to return to Atletico.
The Blues declined to respond to Costa's comments and Conte has recently been reluctant to discuss the player.
In Costa's absence, the Blues lost 3-2 to Burnley on Saturday, the full opening day of the Premier League season.
Costa only wants to move to Atletico, who are under a transfer embargo and cannot register new players until January.
"My desire is to go to Atletico. I have rejected other offers," he said. "If I'm off, I'm going to the club I want to go to, not the club that's paying the most."
The striker said he was happy at Stamford Bridge until Conte made it clear he had no future.
The friction can be traced to January, when Costa missed the Premier League trip to Leicester after a rumoured behind-the-scenes row with Conte and his coaching staff following speculation over a mega-money move to China.
Conte publicly stated Costa's absence was due to a back injury, but the player has now admitted it was for disciplinary reasons.
"That was a punishment for the attitude I had shown and behaving in the best way," he said.
Costa also says he was nearing a new contract with Chelsea at the time, but believes Conte put a halt to negotiations.
Costa was critical of Conte, saying the former Juventus and Italy boss "doesn't possess charisma" and expressing anger over the Italian's communication.
He added: "There are ways of going about it. You don't do it by text. You should be honest and direct to someone's face."