Two Liverpool fans were assaulted prior to the Champions League clash with Napoli on Tuesday.
Both fans were assaulted before kick-off but were able to attend the game.
The police statement read: "At around 6pm local time (5pm GMT), it was reported a number of males on scooters approached the fans at a bar in the city before assaulting them.
"Two men from the UK, aged 26 and 46, sustained superficial cuts and grazes to the head and were treated at the scene before continuing to attend the match.
"Local police are aware and Merseyside Police are working with police colleagues in Naples to assist in the policing of the Champions League fixture."