I read today that Robert Jarni got sacked from his Croatia U17 coaching role for saying he wants Betis to beat Dinamo Zagreb. He's a former Betis player, who also played for and supported Dinamo's main rivals.
I think this is a bit harsh. I mean, let's say Terry Venables had come out and said he wanted Barcelona to beat Arsenal when he was England assistant coach, I wouldn't have held that against him. He was a former Barca manager, he played for Arsenal's main rivals plus Chelsea, in fact he played for and/or managed quite a few London clubs.