Roy Keane has opened up about his rivalry with an “overrated” Manchester United legend and the main “issue” he had with him in his legendary career at Old Trafford. The 52-year-old Manchester United legend is widely regarded as one of the best captains of all time after a remarkable playing spell at the Red Devils. Roy Keane ascended to the captaincy after United legend Eric Cantona suddenly retired in 1997 and was a linchpin midfield figure for Sir Alex Ferguson. The no-nonsense Irishman excelled as a box-to-box midfielder at Old Trafford, coupled with his exemplary leadership skills as capta…