I'd be hesitant to say that the win against Brest means a lot for boosting morale. It was a nice CL-fest. Affirmation of supremacy on the European stage. A message issued to Man City and what not...we'll f...you up when it is your turn...just watch out!
I don't think morale was lost in the first place. The last two away league games could not have been the reason. They were two punches on a chest, part of the business, something you shake off and don't dwell on.