The reason why Harry Maguire was allowed to play on for Manchester United against Fulham - despite the referee advising him to be substituted - has been revealed.Maguire went down in the early exchanges of United's 1-0 win at Craven Cottage with a head injury, following a collision with Fulham forward Rodrigo Muniz.The 30-year-old appeared to accidentally head the shoulder of Muniz as he