If the home fixture against Bayern Munich was one night when Arsenal's defending common sense peaked, the reverse fixture was the exact opposite as they were devoured by a flawless, a rather impeccable Bayern side that simply walked over the visitors. Even if hurt by injuries (again), 5-1 was something of a shock but so was the defending, which had shades of the rudderless Arsenal back-four of the past. Could the case have been different had there been no injuries is an interesting question. The turnaround has to considerably quick, however, if the Gunners are to avoid another damaging defeat, this time in the North London Derby.
Arsenal do know how vital a fixture is this for the rest of the season to shape up nicely, not just because it's a derby, but also because of the fact that after the game on Sunday, they don't face any top side until the 21st of December (Manchester City) in the Premiership. They win this, and they could be out of sight by the time they face their closest title-rivals from Manchester. But it's not going to be easy by any means to take all three points against Spurs.
Mauricio Pochettino's side have been in great form, and haven't lost a single match since their opening day defeat to Manchester United. Dele Alli, Eric Dier, Harry Kane and Toby Alderweireld have all been in good form lately; furthermore, Christian Eriksen looks to be getting back into some sort of rhythm, plus Son-Heung min is returning from an injury as well making Tottenham look even stronger. Surely, Arsenal would have to play their A-game in order to dig out a victory.
Needed for a positive result is a reassessment of Arsenal's defensive plans particularly in the wide regions against a side that has two highly aggressive full backs in Danny Rose and Kyle Walker; not to forget Eriksen and Lamela on either side up front. Anyone who saw Mathieu Debuchy against Bayern Munich would no doubt be aware of what Rose or Eriksen could do to him in a duel. Then again, Joel Campbell's defensive traits aren't that good either making the right flank very weak and ready to be exploited.
The return of Laurent Koscielny, though, may prove to be encouraging in many a ways. Apart from the fact that Debuchy will feel a lot more secured with his French team-mate in the side, the Gunners will be very well equipped to deal with Harry Kane too.
As for the attacking front, a lot will depend on how Alexis Sanchez, Santi Cazorla and Mesut Ozil(who could be tested by Eric Dier) fare in the game. If they are on song, Olivier Giroud will undoubtedly have a massive impact, but if they aren't, the Frenchman mustn't be expected to play much of a role either because he needs someone to feed him the balls in those little areas he gets himself into. Also, Alderweireld and Jan Vertonghen playing high up the pitch would mean Sanchez - who himself has to take care of Kyle Walker - being at his very best to provide support to Giroud who could have a hard day at the office otherwise.
It's hard to call this game considering how good have both the sides been in the league but you still have to say Arsenal have "enough" ammo to go on to win this derby. Yet again, it could be Mesut Ozil dictating the terms.
"It was a disappointing result on Wednesday night but before that we did extremely well in the Premier League," Arsene Wenger said. "We will try to continue from one competition from the other.
"I believe that in the Premier League we have a strong confidence and focus and that is what we want to reproduce on Sunday against Tottenham and, as always, it is a derby. It is always a game where the commitment and nervous force will be important.
"It is not easy [to recover] because it is always a big disappointment [to lose]. When you play against Bayern Munich, and in fact I have watched the game again, not a lot has changed since my analysis afterwards.
"I believe that we created a high number of chances for a game of that stature and offensively, I was quite impressed by the number of chances we created.
"We had not our usual defensive performance, especially for the first two goals, where we gave them the goals basically, that is when it is difficult because Bayern is maybe the best team at the moment in Europe.
"If we had our usual defensive performance, we could have repeated what we had done in the first game.