John Vaughan joined Blues as the club's goalkeeping coach in July 2012.
He is no stranger to Blues boss Lee Clark, having worked with him in the same role when they were both at Huddersfield Town.
Vaughan had a playing career that spanned 18 years and finished in 2000 with Colchester United.
He started out with West Ham United, before going on to serve for Fulham, Cambridge United, Charlton Athletic and Lincoln City amongst others.
After his playing days were over Vaughan moved into the coaching side of the game with York, Macclesfield and Grimsby before linking-up with Huddersfield in 2006.
He holds the UEFA A Licence, and UEFA A Goalkeeping Licence.