In the build up to the game, both mangers were agreed that there was a clear favourite in this tie. Arsène Wenger described Barça as "super favourites" while Luis Enrique ignored the opportunity to politely decline the tag, admitting that "it was kind of logical".
So it should be if you look at it from a purely statistical view point. Barcelona are treble holders, unbeaten in 32 games and have a front three that have scored 213 goals since its conception. But that's not to say the Gunners were dead and buried before a ball had been kicked.