Manchester United have been sharpening up the coaching staff ahead of the upcoming season. Eric Ramsay, Benni McCarthy, Steve McClaren and Mitchell van der Gaag have all left Manchester United’s backroom team this year, despite Erik ten Hag staying on. All are pursuing new opportunities, given Manchester United the chance to freshen up the coaching staff. Along with Rene Hake and Andreas Georgson, Ruud van Nistelrooy has rejoined the club, bringing a familiar and high profile face to Carrington. READ: Who is Ruud van Nistelrooy? Inside the life of Man Utd legend, including his PSV management a…