Maybe not the worst, but the one that's annoyed me the most since I started going in the late 70's is Nigel f¤¤king Callaghan.
I think Nigel Callaghan would be top of my list ...he just didn't show any interest.Andy Weimann would not be anywhere near the top of my list, was actually quite disappointed he left, good squad player.
Mine would be Andreas Weimann. I don't wish the guy any ill but hells bells he was absolute garbage. Hoodwinked many of our parish into thinking he was ok because he ran around a lot but in all facets of the game he was, to put it politely, found somewhat wanting. Being played out of position didn't help but then there isn't a position on earth that could accommodate a 'footballer' like him. I'd sooner have played with ten.