I'm an Italian supporter of Napoli. I may help you to understand this situation about De Rossi.
First of all, he's a good player. Probably the best Italian midfielder after Prilo (but i may admit the others aren't so good...). In Roma he's called "Capitan Futuro", you may understand it's meaning, the captain of tomorrow, since today the captain is Francesco Totti. De Rossi is from Roma, he's a supporter of that hateful team, and he'd love to play there as long as he can. But there's a problem. The owner of Roma is now the American De Benedetto, but it looks like still Unicredit, a bank, has an important role in the society. Actually, Roma is not a rich club, and it can't give to De Rossi (which i remind you, is going to be 29 this year) all the money that, according to media, Real Madrid and City could. So those are the scenarios: Roma gives a lot of money to De Rossi, less then Real or City, but still a lot, and he stays in Roma; Roma can't give enough money to De Rossi and will try to sell him this year or he will go for free to Real or City. I don't know if you're really interested in him, but media always say Real, City and PSG because those are the clubs that can buy.
I hope i helped you somehow.
PS it doesn't mind if he played or not against Fiorentina in Coppa Italia. In this competition usually the greatest player don't play till the very end.