On Wednesday evening, it could prove to be a pivotal day in Arsenal's quest for Champions League glory.
If Arsenal don't manage to gain at least a point against Borussia Dortmund at the Westfalenstadion, it will put the Gunners in a sticky position in their group, especially if Napoli beat Marseille.
This would leave Napoli and Dortmund on nine points apiece, with Arsenal in third place on six.
If Arsenal do beat Marseille and Dortmund beat Napoli, this would leave a fight to the death between Arsenal and Napoli on match-day 6. At the moment, Arsenal have a superior goal difference to Napoli by two goals, but this could drastically change in the next month.
Also, it must be considered that Napoli have a chance of beating Dortmund as they've already defeated them in match-day 1 of the Champions League when they lost 2-1. This would be a quite drastic result for Arsenal as that would leave themselves and Dortmund on nine points with Napoli leading on 12.
Going into the final week, Napoli could afford to draw and end the group campaign with 13, which would leave Arsenal on 10. Dortmund would be expected to beat Marseille and end on 12.
Although these predictions are going on past results and the quality of the teams, football has proven time after time how unpredictable it can be. Two years ago, not many people believed Manchester United would falter in the group stages when they had teams such as Basel, Benfica and Otelul Galati.
Arsenal will be going to Dortmund with a boost in confidence if they ever needed it after a convincing performance against Liverpool. They will also be encouraged that they did play well against Dortmund just two weeks ago, but they must be more cautious this time around.
Jurgen Klopp will undoubtedly change his team's tactics as they're playing at home, and they'll be expected to dominate possession.
It's games like these where Arsenal will really miss the likes of Theo Walcott, who is expected to be fit for Manchester United on Sunday, and Alex Oxlade-Chamberlain. With their pace, it gives Arsenal a great outlet to counter-attack and it's especially useful in the Champions League.
Dortmund were a great example two weeks ago, when they scored their second goal against the Gunners with a blistering counter-attack.
A lot of pressure will be on Olivier Giroud for the rest of the Champions League campaign in particular, especially after a solid performance against Dortmund and Liverpool. He will be pivotal against the likes of Dortmund and Napoli where Arsenal's midfielders will have limited space and will constantly be pressured on the ball.
If Arsenal are to get through this group, they must accelerate the delivery to Giroud. This was on of their biggest problems against Dortmund, as they couldn't get him involved enough in the game. When they gave him quick service, such as Bacary Sagna's cross, it gives the Frenchman a great chance to get a goal.
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