people might make Napoli the Favorite against milan, but the fact is that milan humiliated Napoli with 4 goals without reply in front of their supporters, this will be an important lesson for Napoli for their meeting against milan later in the UCL, while madrid and chelsea meet. I don't think anyone can predict that but people always underestimate Chelsea. even though if we see that they reached the UCL quarter-finals it was not something easy, they worked hard for it so against Madrid of course Chelsea had prepared for that.
Yeah no one expect Napoli got humiliated by AC Milan, usually even Napoli is lose, the margin difference is just 1-2 goals. But the situation between AC Milan and Chelsea are different, Stefano Pioli is still managing AC Milan until now and AC Milan have Rafael Leao which is one of the best left winger.
Chelsea don't have any star player, just a good player since there's no one can carry Chelsea during bad performance. Graham Potter was been sacked and they're trying to find a new manager. Currently Bruno Saltor is managing Chelsea, he haven't managed any club in his whole career.