Manchester United’s Portuguese head coach Ruben Amorim reacts during press conference at Old Trafford in Manchester. [AFP] Manchester United coach Ruben Amorim said he cannot explain why the club’s fans and board are backing him despite the team’s dismal domestic form ahead of Wednesday’s all-English Europa League final. The Red Devils are having their worst top-flight campaign for 50 years, since they were relegated in 1974 but the coach is not under the same pressure as his opposite number in the final, Tottenham’s Ange Postecoglou. United have not won any of their last eight Premier League matches but their thrilling…