The striker, who already has 14 goals to his name this season, has fallen out with his manager and has not travelled with the squad to face Leicester
Diego Costa's future at Chelsea is in doubt after a "blazing row" with Antonio Conte, according to Daily Mail.
The striker reportedly has not travelled with the squad for Saturday's trip to Premier League champions Leciester City, with Costa complaining of pain in his lower back.
Chelsea's medical staff are not convinced by Costa's prognosis and Conte has sided with his backroom team.
Furthermore, Sky Sports claim that the Spaniard has been unsettled by a £30 million bid from a Chinese Super League club, with his agents said to be angling for a lucrative deal.