I thought Dortmund did a great job of closing down all over the pitch - as they always do.
You guys missed Flamini. Ozil was invisible for most of the game, Wilshere showed that he's not a winger - always a beat off, and Ramsay look bun.
After the goal, you picked up the pace, which helped, but for the most part, both teams neutralized each other, On the winning goal, somebody didn't track back and pick up Lewandowski. Sagna was in that position on the team sheet, but was playing right wing whole game, Ozil, probably.
This is the first game this season where I can say that Arsenal was missing Walcott and Podolski.