The Italian, who coached the Giallorossi from 2009 to 2011, said that he admired his successor Luis Enrique's attacking mentality, but that it left spaces in the defence to exploit.
"It will be a good match, and important for both of us to win," Ranieri told La Gazzetta dello Sport.
"They attack and create a lot of chances but they leave a lot of space at the back and we'll have to stay on our toes and exploit those spaces.
"Roma made an excellent move by bringing in Luis Enrique," added the 60-year-old.
"He has demonstrated that his team had an idea and the players went along with him. He's doing well and he'll do even better."
The veteran boss has many fond memories of the capital and is looking forward visiting the club that he took to last season's Coppa Italia final.
"From a personal point of view it's always nice to return here, but we have to look ahead now," he said.
Ranieri also indicated that he would rest midfield maestro Wesley Sneijder for the clash, who was injured in Inter's 4-4 draw with Palermo in midweek.
The Dutchman's injury looked serious at first, but scans revealed only minor damage.
"All the tests were negative, which is good news because I was worried," the coach confessed.
"He won't be playing [against Roma], but I hope to have him back for the Novara match."
The Serie A clash may see an Inter debut for new signing Fredy Guarin, who arrived on loan from Porto at the close of the January transfer window.
Roma enter the match in sixth place in Serie A, one place below the visitors, who hold a five-point lead over their opponents.