Chelsea have been rocked by a demand for a loyalty bonus from Diego Costa.
Costa claims he is entitled to the payment, as he is being forced out by manager Antonio Conte.
It is believed that the bonus demand, forms part of his legal case against the Stamford Bridge outfit.
It also comes despite the Spain striker openly admitting last season, that he wanted to rejoin his former club, Atletico Madrid, only to have his exit vetoed by Conte.
Speaking in the Spanish media, the £140,000-a-week star said last August: “Everybody knows there was a possibility of going back to Atletico but it didn’t happen because of a few details.
“Now I’m at Chelsea, I’m happy there and I’ve started the season with them. I hope Atletico do well this season like last year and win titles. I wanted to go back, I won’t lie about it.”