Anthony Martial’s failed Manchester United career symbolises the club’s decline and Wayne Rooney is a gamble worth taking for Everton

If you were looking for a single figure to sum up Manchester United’s malaise in the last decade, you wouldn’t be short of options.From a deadline day dash to sign Marouane Fellaini in 2013 to the £6m loan signing of Radamel Falcao, United have made blunder after blunder since Sir Alex Ferguson’s retirement.But while there’s been countless failures, nobody quite symbolises United’s decline quite like Anthony Martial.The Frenchman arrived at Old Trafford in 201