I'm wondering what Arsenal will do as of this stage in the Champions League. They had a successful group stage as expected. Now I can say that they have a comfortable matchup to play against Porto as well. Because I don't believe Porto are one of the teams that can eliminate Arsenal in this tournament. Porto couldn't even beat Barcelona in the group stage. I mean that Barcelona aren't weak of course but I don't think they have played better than Arsenal at all. 
Anyway I see Arsenal in the quarter finals already to tell the truth. But they had better improve their performance more as there is some decline recently.
When Arsenal was drawn against FC Porto in the round of 16 of the UEFA Champions League, I expected Arsenal to win against FC Porto but with the recent performance of Arsenal, I'm not sure if Arsenal could be able to beat FC Porto. If FC Porto can play well in their home, I believe they will beat Arsenal. Anyway I see Arsenal in the quarter finals already to tell the truth. But they had better improve their performance more as there is some decline recently.
The next Champions League game is still a month away, Arsenal have time to recover and have a great game against Porto, it's too early for them to denigrate the defeat when they could well be off to a decent start in their league. Even if things are unstable, I'm still leaning towards Arsenal going through, they are superior to their opponents on all accounts