Arsenal's performance in the domestic league is quite poor and that could be a stumbling block for them before the first leg starts. The Gunners squad's readiness must be arranged neatly considering that the Champions League is more difficult than the domestic league that they often encounter.
Porto is not an easy opponent, they could have beaten Arsenal if Arteta had not made a good strategy for their match in the first leg. Of course, the bad results obtained in the domestic league must be paid for in the UCL. At least Arsenal can succeed in getting a win in the first leg. although it is not easy enough for Arsenal to beat Porto. As long as Arteta maintains the performance of all his players, I'm sure they can qualify for the next round.
It's difficult to divide focus in the UCL and in the domestic league, especially as the competition at the top of the EPL standings this season is also very tight so it seems Arsenal will again fail to win the title in the EPL this season for the umpteenth time, at least they might be able to focus much more on the UCL this season, although Not being UCL champions this season, at least they showed their ability to make it to the semi-finals, that's already good
Porto was of strong team. Even though we are rarely seeing the performance of porto in its domestic league but it's still competing for the top place in the portugal league. Arsenal shall never try to underestimate its opponent. It can make the players become over confidence and they will be starting to bottling the important match against porto. This is the bad habit owner by arsenal as it was always failing to go to the further stage of UCL. Arteta shall also aware if this is the main problem that needs to be solved.
He needs to push his player to perform even better compared to the previous game. Arsenal was getting easy team in the group stage but this time is kinda different. It's not facing a weak team. Arsenal needs to be careful if the team is willing to win the game.
Im not counting on arsenal caused by porto and arsenal are same strong. Neither of them will be dominating the game soon.