Antonio Rudiger was reportedly dismissed from Chelsea's training session on Sunday after an altercation with teammate Kepa Arrizabalaga.
Neither Rudiger nor Kepa was involved in Saturday's shock 5-2 loss to West Bromwich Albion in the Premier League, which came off the back of the international break.
However, according to The Telegraph, a heated dispute took place between the two players after a late challenge on the second-choice goalkeeper during Sunday's training session.
The report claims that the pair had to be separated before the central defender was sent back to the changing room by head coach Thomas Tuchel five minutes before the end of the small-sided match.
Rudiger is believed to have since apologised to his teammate and head coach Tuchel, who is preparing the team for Wednesday's Champions League quarter-final first leg with Porto.
Chelsea remain fourth in the Premier League table, but they would drop down to fifth if West Ham United manage to beat Wolverhampton Wanderers on Monday evening.
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