Hansen wrote in the Telegraph: "Bayern's dominance in Germany could prove their undoing because if you win every week, complacency inevitably creeps in. You begin to think that the game is all over before it has even started and some of their winning margins this season have given that impression.
"But the Champions League is a different matter and what some people have forgotten is how close Arsenal came to knocking them out at this same stage last season.
"Arsenal were outplayed when losing 3-1 at the Emirates, but they won 2-0 in Germany and had the second leg gone on for five more minutes, Arsène Wenger's team would have gone through.
"I am sure Arsenal will gain confidence from that, but they must stand up to the fight when they face Bayern again this week."