Liverpool striker Darwin Nunez was unhappy during their 3-2 loss to Toulouse in the Europa League.
Naming a rotated line-up for the group stage contest, the Reds were unable to get any points in France.
During a tough game that saw them create many chances, a late VAR decision denied the Reds an equalizer late in the day.
Reds forward Nunez, who struggled to influence the game, had an argument with Toulouse goalscorer Frank Magri.
The incident resulted in Nunez getting a yellow card, while he was also angrily arguing with the referee at one stage.
And ater the final whistle, he went to shake the hands of his opponent before realising it was Magri and quickly withdrew his offer.
The Reds will be hoping that Nunez can be on his best behavior when they take on Brentford in the Premier League on Sunday.