Former Arsenal striker Charlie Nicholas says they must be at their best against Champions League opponents Borussia Dortmund.
Nicholas wrote in the Sunday World: "Three points from their trip to Germany will be enough to see Arsene Wenger's men through to the knockout phase. It's a huge game for the Gunners this week. The winners of this showdown will probably top the group. As we all know there is a massive difference between finishing first and second in your section.
"In fairness, I also don't believe any of those teams would fancy playing Arsenal at that stage of the competition. But Wenger won't have to worry about that if his team win this week. This is the key game, where first spot is concerned."
