To be honest I'm sure he would be verbally abused the same way that anyone weraing a catalan NT in Madrid for instance. That's the same on both sides.
The diffrence is that in Catalonia or basque country people living there can think whatever they want. The problem is when people from other areas of Spain is always telling us how you have to live, speak or feel at our home.We are never questioning how people have to live, speak, feel in madrid (i.e
. Catalans would be happy in a Spain where our culture and feeling are respected, We don't want to impose it anywere but we want to keep it here . That's all.
I would support a spanish team representing this idea. I can not support a spanish football team cheered with spanish flags with bull in the center (which is a methaphor of the old Spain and it's values: bullfighting, centralism,...). As I said before , the basketball team looks a bit different .