Reports from England claim Diego Costa had a traning ground bust up with Chelsea boss Antonio Conte after received a lucrative transfer offer from the Chinese Super League.
Sources at the club who spoke with ESPN FC claim Costa has trained alone at Cobham for the past three days after becoming embroiled in a heated argument with a fitness coach over an injury.
Conte however got involved and decided to punish his striker after siding with his staff in the dispute.
Chelsea head to the King Power Stadium on Saturday hoping to preserve their five-point lead at the top of the Premier League.
Costa is the division's top scorer with 14 goals in 19 appearances this season, has not travelled with the rest of the squad for the clash with the Foxes.
Chelsea declined to comment on the matter Friday however Costa posted a support message for Chelsea in Instagram.
According to the Telegraph, a Chinese club has informed the Spain international they are willing to offer him £30 million-a-year after taxes to leave Stamford Bridge in January.
Costa's contract runs until June 2019 and while Chelsea were reportedly keen to tie down their star striker to an extension prior to the recent dispute.