So far there are no problems reported around the Coppa Italia Final, though Roma fans could be set for a surprise.
The game kicks off at the Stadio Olimpico at 17.00 UK time (16.00 GMT) and the ultras have made a pact to avoid clashes around this historic event.
There are over 2,000 riot police deployed in the city and supporters from each club have been told to approach the stadium from a different side to limit encounters.
The gates are due to open at 13.30 UK time and there is a packed pre-game schedule, including a performance by Psy.
Lazio fans are expected to impress with their choreography, unveiling a giant banner that covers both the Curva Nord and the Distinti section of the stadium.
So far Roma have not announced any choreography, which some claim is a protest against the disappointing season.
Others believe this is only a tactic so the ultras can spring a surprise on fans and players alike.
Giallorossi fans have been urged to attend wearing red and yellow, attempting the replicate the ‘wall’ of colour used by Borussia Dortmund.
There are reports an arsenal of weapons was discovered by the river near Ponte della Musica, where the Roma fans were due to pass through.
The Stadio Olimpico will include buffer areas in the stands, reducing the capacity to 63,000.