Napoli are a promising team in the Champions League as well. They only need to keep the same motivation after the return of this break. In that case they can have one of their most successful seasons in the Champions League as well. Frankfurt is an easy target for them of course. I don't expect any surprises.
But by the quarter finals, things are going to get really serious. They are most likely to have a draw against big title contenders. If they somehow get a lucky draw then they can reach semi finals easily. The luckiest one would be the winner of Milan - Tottenham or Club Brugge - Benfica matchups.