As Casemiro gift-wrapped Arsenal’s only goal of the game at Old Trafford, ambling out of the backline while playing the visitor’s frontline comfortably onside, any remaining goodwill towards him from an irate Manchester United fanbase disappeared for good. We’ve seen 40-something Sunday League plodders after a night on the Carling and the kebabs move quicker than the Brazil international. Another calamitous and seemingly half-hearted display from a man at the scene of the crime yet again only six days after that Crystal Palace capitulation. And Rio Ferdinand, a man who knows a thing or two abo…