Jurgen Klopp gave an honest assessment on Liverpool's performance after a 4-1 loss to Napoli in the UEFA Champions League.

The Reds were torn apart in the first half at the Diego Armando Maradona Stadium with goals from Piotr Zielinski, Andre-Frank Zambo Anguissa and Giovanni Simeone before Zielinski bagged his second of the night at the start of the second half.

Despite their superior ball possession, Liverpool could only muster a consolation through Luis Diaz.

Speaking after the match, the German coach admitted his side played one of their worst games throughout his time at the club.

"That was the least compact performance I’ve seen from us for a long, long time. Napoli were really good, but we made it easy for them.

"We lost the ball in areas and then the next situation was a counter-attack, but that’s not how it should be.

"A few things are really clear. We have to change that and the reason why it’s now like this [is] getting a bit more clearer as well, but I need time for just saying the right things, not 100 per cent in the moment," he said.

Klopp also apologised to the travelling Liverpool fans for the shambolic defeat.

"It’s a long flight from Liverpool to Napoli. For all the things they invest, I understand 100 per cent it was a very disappointing night so, of course, I put up [my hands], I have to say sorry for that."