Manchester United manager Erik ten Hag says his side "lost their heads" in the 7-0 thrashing by Liverpool on Sunday.
The defeat was United's joint heaviest in a competitive game while it was Liverpool's biggest-ever win against their rivals.
Ten Hag's side were 1-0 down at the break before letting in six goals in the second half at Anfield.
"Second half it was not us. It was not our standards. We didn't play as a team," said Ten Hag.
Asked if he was angry with his side's second-half display, he added: "Yes definitely, and surprised because I have seen the last weeks and months a team that is resilient and determined with a winning attitude.