Scenes of violence and disorder marred the two clubs' Champions League games last season, although the October meeting at Old Trafford passed off peacefully.
In his programme notes for the Aston Villa match, Ferguson said: "My main concern as we plan for Tuesday is the safety of our travelling fans.
"Last season the Italian police made a hash of security in the ground and a few of our people were hurt.
"That was put right when we went to Rome in December but there was still danger on the streets and a number of stabbings.
"I urge everyone who intends to go to Rome to heed the security advice so everything passes peacefully.
"Hopefully then we can concentrate on a testing but exciting match."