#2 Complacency could set in

As indicated, Barcelona is the overwhelming favourite to triumph in the match. Their history, calibre of players, and recent dominance of this competition guarantee that.
However, they were also favourites to progress to the final of this season's Champions League having posted a 3-0 first-leg advantage over Liverpool as well as last season against AS Roma, but in rather shocking scenes, La Blaugrana failed to press home their advantage, crumbling in the face of pressure when everything was seemingly set for them to triumph.
Barcelona's superiority could see them enter the match with a feeling of invincibility, effectively seeing themselves as victors before a ball is kicked.
Football is a game of 11 men apiece and while Barcelona might have better players, Valencia can take solace in the fact that the Catalans have a history of being complacent when the odds are stacked in their favour, and their status as underdogs could see them triumph, as football is a game where anything can happen.