Liverpool manager Jurgen Klopp has admitted that his players had been left 'frustrated' by Paris Saint-Germain on Wednesday night.
The Merseyside giants succumbed to a 2-1 defeat at the Parc des Princes in a game which saw the Premier League outfit receive six yellow cards.
However, replays suggested that some of Liverpool's fouls were exaggerated by the home side, and Klopp suggested that he had been left unhappy by the conduct of some of the opposition.
The German is quoted by BBC Sport as saying: "I know it will be the headline, but the number of interruptions in the game was not cool.
"We won the fair play award two times in England and tonight we looked like butchers with the number of yellow cards. It was clever of PSG, especially Neymar, but a lot of other players went down like there was something serious.
"We were not that calm anymore, rather frustrated and negative frustration does not help. That is a job for us to deal with."
Liverpool must win their remaining Champions League group-stage fixture against Napoli to keep alive their hopes of progressing through to the last 16.