Facing porto will clearly be a big challenge for roma, especially with their unstable and consistent this season in undergoing every match there is, the draw against napoli indeed shown the mentality and unyielding attitude which their have for rise towards the end of the match, but often conceding in the first half actually makes me doubt if they can withstand the aggressiveness of the attack owned by porto later, Moreover, from the head to head of the two teams so far, Porto is superior to Roma and this shows that Porto is often a difficult opponent for Roma in European competition, but apart from that maybe Ranieri experience and ability on coaching so far, can be a differentiator and also increase their chances of winning in the match, although I personally tend to be more confident that Porto will win over Roma  .