Rio Ferdinand has admitted that he was blown away by what two former Manchester United teammates did during his “first-ever pre-season” at Old Trafford. Sir Alex Ferguson brought Rio Ferdinand to Old Trafford after Manchester United signed him from rivals Leeds United for a £30m fee in 2002. Ferdinand, who was a British record signing for the second time, became a key defensive figure for legendary former United manager Sir Alex Ferguson. The 45-year-old former United defender went on to make 455 appearances at the Red Devils and enjoyed incredible silverware success at Old Trafford. Ferdinand…