He did beat them twice in the last two seasons, so why not?
I don't really know, tbh. It depends how motivated his team is. Being eliminated in Europa league and missing out on the win the way they did in Naples last week, must have some consequences on the team morale.
With the way teams outside the top 3 play, Ranieri knows that the 3rd place is guaranteed while winning the second place will be good, but not of very high importance. What counts is the scudetto and Roma are 7 pts behind it. I wonder how motivated they'll be for tonight's match.
On the other hand, there isn't so much pressure on him and his players as there is on Milan, who are not only in the scudetto race, but they also have a return leg to play in Manchester in midweek.
I read from you that there'll be full house in Olimpico tonight, so the least we can expect is a good match, well worth watching.