West Ham’s £25m man Luis Guilherme has given the game away with an exciting post on social media ahead of his big unveiling. Most West Ham fans refuse to believe a deal is done until they say one of two things. A picture of technical director Tim Steidten on a plane with the player and his agent. Or the player in question actually holding up the West Ham shirt having signed on the dotted line. The latest transfer collapse involving Fabricio Bruno only served to underline that for West Ham supporters. And that deal had looked home and hosed transfer reporter Fabrizio Romano gave it his trademar…