#3 Diving and play-acting
This is a no-brainer; even Barcelona fans have to admit this.
In the modern game, deceiving referees has become something of a dark art. Managers tell their players to avoid it, but every player knows that in the dying minutes of a must-win fixture, it's the most useful tool to win a penalty that could save the game. As bad as it might be, it's become common, and clamour for video technology has largely been centred around the inability of 40-something-year-old referees to keep up with the blistering pace of 20-something-year-old divers at the other end of the pitch.
Yet over the past decade, Barcelona players tend to have fine-tuned this art into a perfect technique. Neymar, Xavi, Busquets, Dani Alves and even Arsenal's super-human Alexis Sanchez have put in some Oscar-worthy performances to dupe referees into sending off their opponents. For a team with so much quality, is that really necessary? We can't accept that it is.
Despite their relatively short size, Barcelona have some very powerful players in their ranks, but the sheer number of complaints from opponents about them falling like leaves in the wind, must surely make one grit their teeth. Diving, rolling and deceiving the referee are acts that shouldn't be part of the beautiful game.