Kepa Arrizabalaga reportedly had a row with fellow Chelsea goalkeeper Willy Caballero in the aftermath of Sunday's EFL Cup final defeat to Chelsea.
The Spain international stole the headlines following the Blues' 4-3 loss on penalties for his refusal to follow manager Maurizio Sarri's instructions.
Sarri wanted to bring Kepa off for spot-kick specialist Caballero, but the world's most expensive keeper was having none of it and stayed on the field.
According to The Sun, the 24-year-old further angered Caballero in the Wembley dressing room by claiming that he is the better goalkeeper, leading to the two men squaring up.
Kepa has been fined a week's wages for the on-the-field incident, which is rumoured to have split Chelsea's playing squad down the middle.