Sir Alex Ferguson hit the nail on the head with a spine-tingling spell that he delivered to Manchester United players during a key moment in his career. That is according to Manchester United legend Jaap Stam, who opened up about his time under legendary former Red Devils manager Sir Alex Ferguson. Ferguson is widely considered as one of the best managers of all time after his impact in England with United and in Scotland with Aberdeen. The 82-year-old Scotsman enjoyed incredible success during his legendary spell at Old Trafford, including lifting 13 Premier League titles with the Red Devils….