Jurgen Klopp sported a tricolour badge in a show of support to the Irish fan viciously assaulted outside Anfield this week.
The Liverpool boss sent a message of support to Meathman Sean Cox and his family after he was left in a critical condition in hospital following an attack prior to the Champions League fixture against AS Roma on Tuesday night.
Speaking at Melwood on Friday the Reds boss said: "I think the game on Tuesday night showed the beauty of the game during the game - and showed the most ugly face of parts of the game before the game.
“When I heard first time about it I cannot describe my emotions in English, to be honest. It was how it feels still, that it should never have happened.
“It should never have happened before and it should never happen in the future, and we all have to do everything to make sure that things like that will not happen anymore. It’s obviously not the solution for it, probably nobody has that.
“It’s just unbelievable that something like that can happen. How you can imagine with all our thoughts and prayers with Sean and his family at the moment.”