Losing 1-0 to Porto in the first leg was really unfortunate for Arsenal as they played quite overwhelmingly but did not score a goal. Porto is always an unpleasant opponent in the UCL, but looking back at the teams entering the qualifying round, this is a much easier opponent for them. Hopefully the Emirates home field will help Arsenal play more confidently and win against Porto in the second leg.
The first leg was really painful for Arsenal who came quite spectacularly after previously winning in the league with a big score but they had to lose at home to Porto without even having a single shot at the opponent goal, Arsenal game in the first leg was actually quite good and was even able to continue to dominate the game throughout match, but the tight defense built by Porto meant that all attacks carried out by Arsenal were able to be overcome by Porto defense outside the penalty box, the defeat against Porto was actually a warning for Arsenal because they currently need a striker who is capable of being the difference between if Arsenal wing attackers experienced a deadlock.
The second leg will be a match that can be said to be life and death for Arsenal in the Champions League, because if they lose or even draw then it is certain that the Champions League will end too quickly for Arsenal, but Porto cannot underestimate Arsenal at home because after all Arsenal is a team that is quite dangerous when playing in front of its own supporters, I think in the second leg the Arsenal players will play all out to at least be able to catch up on the goals left behind and maybe even a big win will be achieved by Arteta team later in emirates stadium.