Chelsea firebrand Diego Costa feels he's been betrayed by manager Antonio Conte this week.
Costa believes he has a lower back problem, which could be linked to his history of hamstring injuries.
But Chelsea expected him to train this week as part of Conte's strict fitness regime.
The Daily Mail says this sparked a series of blazing arguments, with Conte backing his medical team and leaving Costa flabbergasted.
The disagreement has led to a rift between Costa, Conte and the Chelsea physios. The striker does not agree with their methods and has pointed to his impressive record this season, when he has scored 14 league goals.
Chelsea had planned to offer Costa a new contract but that is now in significant doubt, although the forward is prone to such fallings-out and the club hope the matter can be resolved.