Owen Hargreaves questioned Ruben Amorim’s substitutions in Manchester United’s 3-2 defeat to Nottingham Forest yesterday, and called Amad Diallo the only “undroppable” forward. Speaking on Premier League Productions, via Football365, the former United midfielder registered his disbelief that captain Bruno Fernandes was withdrawn with the hosts desperately chasing a goal. “I was amazed he went off,” he said. “He created…