The teenager's arrival from Chelsea - on a season-long loan, with an obligation for the Magpies to make the move permanent next summer - was confirmed on Tuesday morning and he has now joined his colleagues in preparing for the Premier League clash with Jürgen Klopp's side on Sunday (kick-off 16:30 BST).
Hall became United's fifth signing of the current window, with Yankuba Minteh on loan with Feyenoord, Harvey Barnes and Sandro Tonali both scoring on their debuts on the opening day of the season and Tino Livramento making his bow as a substitute at Manchester City last weekend. Now Hall - a boyhood Newcastle fan - could pull on the black and white shirt for the first time on Sunday.
Club photographer Serena Taylor brought nufc.co.uk this gallery.