Chelsea are furious with former goalkeeper Thibaut Courtois after he accused club director Marina Granovskaia of reneging on an agreement to sell him last summer, Sky Sports News understands.
The Belgium international said he was informed by the Blues that he would not be sold following the World Cup, despite previously being told he would be allowed to leave.
As a result, Courtois did not to return to Chelsea training ahead of the new season, forcing Chelsea to allow him to move to Real Madrid on Premier League Deadline Day.
He told Belgian newspaper HLN: "That Marina is hard at negotiation is normal. The people in football who are talking about contracts, salaries, transfers, etc that get players and dispose of them - they have the most difficult job.
"In March, Marina and I had a meeting in which I indicated that I wanted to leave. Living in London and the schedule of the Premier League made it impossible for me to regularly see my children, who lived in Madrid.
"After the World Cup, a departure was suddenly not that obvious anymore. The possible replacements were too expensive. That was not the agreement."
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However, Sky Sports News understands that, despite Courtois telling Chelsea several months earlier that he wanted to leave, Granovskaia made no promises about allowing him to do so.
Courtois spent three seasons with Atletico Madrid before establishing himself as Chelsea's No 1, and says he wanted to return to the city in order to be closer to his children.
The 26-year-old eventually secured a £31.5m move to Atletico's city rivals Real, with Chelsea signing Athletic Bilbao goalkeeper Kepa Arrizabalaga as his replacement for £71.6m - a world-record fee for a keeper.