Around 50 West Ham United hooligans have arrived to infiltrate Roma-Lazio, while Wisla Krakow fans are also expected.
The Derby della Capitale kicks off at the Stadio Olimpico at 14.00 GMT on Sunday.
This is a high-risk game, but the stadium will be half-empty because ultras from both clubs are boycotting the Curve – ends – over new barriers introduced to split the sections.
This increases the likelihood that groups of fans will clash away from the stadium, where it is more difficult to police the streets.
According to La Repubblica, around 50 West Ham United hooligans have been spotted in the city for tomorrow’s game.
They were invited by Lazio’s more hard-line and violent supporters.
There are also concerns that hooligans from Wisla Krakow and Real Madrid’s Ultras Sur will turn up, although so far they haven’t been identified.
Rome has already been devastated by foreign hooligans this year, as Feyenoord fans damaged a priceless fountain in Piazza Navona ahead of a Europa League match.