By David McDonnell On Saturday, Manchester United return to the scene of one of the most humiliating results in the club’s recent history. United have suffered some embarrassing losses in the post-Sir Alex Ferguson era, most notably last season’s crushing 7-0 mauling at arch rivals Liverpool. But the 4-0 defeat at Brentford last season saw Erik ten Hag lose his first two games in charge and left United rock bottom of the Premier League on zero points. It led to legitimate questions about Ten Hag’s suitability to manage United, with the emphatic loss coming on the back of a 2-1 home defeat to B…