Politics.
In 30-60 days, half of a forum will hate half of our players, former players (Xavi), coaches (Pep) and similar.
If 50% of Catalans (or whatever the number is) are against an independence, then it is quite likely that half of our players are for and half of players are against it also.
For every Pique, there will be one Busquets in our team.
Not only that fans will start to hate some of our players, but players in our team will also probably start to hate eachother (to some extent) because of politics.
As always, when it comes to politics and rocky times, there are only 2 sides, either you are with us or you are against us.
And that will cause a lot of problems.
Btw, exactly the same problem happened in my country (Croatia) 25 years ago and to some extent, it never ended (it evolved) even 25+ years later.
So, yes, it will be: either you are with us or against us among fans and players especially if a political situation will escalate further into uglier levels.
Tough times are infront of us.
A problem totally unrelated to player's skills, coaches, tactics, motivation, injuries, opponents, luck, referees etc.