The decision to call the match off was taken by the city council after an 'orange' weather warning was issued.
Forecasts showed heavy rainfall in the area from 2pm local time on Saturday, with the match at the Stadio Luigi Ferraris scheduled to kick off at 845pm.
The news means Eusebio Di Francesco's squad will have extra time to prepare for the visit of Atletico Madrid in the UEFA Champions League on Wednesday morning AEST.
Roma also delivered an update on the fitness of new signing Patrik Schick, who would not have been in line to face his former club after scans on Friday revealed an oedema in his left quadriceps.
He will undergo further tests in the next two days.