In his pre-match media conference, Arsene Wenger called this Champions League clash with Dortmund an “80 percent” game. Should Arsenal manage to beat the German side, they will be approximately 80 percent of the way towards qualification. 
There is some logic behind Wenger’s numerical guesswork. A win would take Arsenal to nine points, six clear of Dortmund. With three victories from three games and a very winnable home tie with Marseille still to come, Arsenal would be all but certain of progression to the knockout phase. 
However, it’s all easier said than done.
This is a significant match for Dortmund too—not least because they’re returning to the city where they lost the 2013 final to rivalsBayern Munich. Dortmund also have bad recollections of the Emirates Stadium: they lost 2-1 there during the 2011/'12 season. The Germans will be keen to banish two sets of traumatic memories and leave with all three points. Having already lost against Napoli, every point is precious for Juergen Klopp’s side.
For their part, Arsenal have a relatively good record at home to German sides in Europe. In 13 games against German opposition in London, Arsenal have won nine times. However, the Bundesliga’s recent resurgence suggests that the tide is turning.

With both teams desperate for the points, the indications are that this should be an exciting encounter. Arsene Wenger is inclined to agree. Speaking to the club’s official website, he said:
What they give you, the German teams, is they have a desire to play. They play with a positive attitude and they have produced as well many good players recently.
It makes it always an open game because they don't hide. We don't hide, so it should be an exciting game on Tuesday.
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There are many individuals for whom this is a particularly big game. Tomas Rosickyfaces the club he played for between 2000 and 2006. Wojciech Szczesny will line up against two of his Polish international teammates: Jakub Błaszczykowski and RobertLewandowski. Meanwhile, Arsenal’s German contingent, featuring the likes of MesutOzil, Per Mertesacker and Serge Gnabry, will be especially keen to impress against their countrymen.
Arsenal have not failed to get out of the group stage since the 1999/2000 season. However, Group F is arguably the toughest draw they have ever faced. 
Should Arsenal beat Dortmund at the Emirates Stadium and edge to the brink of qualification, Gunners fans will rightly see it as yet another sign that their team is emerging as a serious contender for silverware this season.