Mauricio Pochettino says his Chelsea side "gave up" during their damaging 5-0 defeat by Arsenal at Emirates stadium.
Having gone into half-time 1-0 down, the Blues conceded four goals during a devastating 18-minute spell in the second half as they fell to their heaviest defeat in a London derby since 1986.
Pochettino had made three changes to his defence for the game, opting to rest Trevoh Chalobah and Thiago Silva, while Malo Gusto sustained an injury during Saturday's FA Cup semi-final loss to Manchester City.
"It's not difficult to explain," said Pochettino.