Newcastle United were absolutely the architects of their own downfall against Manchester United. Yes, Anthony Gordon was seriously unlucky not to have been awarded a penalty in the first-half of what turned out to be a 3-2 defeat at Old Trafford. Indeed, Newcastle even had chances to score, with the likes of Alexander Isak and Sean Longstaff failing to convert when through on goal. All of that is hugely frustrating of course but Newcastle only have themselves to blame for the goals they ended up conceding. Kieran Trippier, enduring something of a nightmare campaign as it is, let Kobbie Mainoo …