Steve Watson initially joined Blues as a coach in August 2012, and was responsible for supporting the under-21 development squad manager, plus assisting boss Lee Clark with first team coaching duties. After 19 moths in that position, Watson was appointed to role of assistant manager by Clark.
Watson had previously worked under Clark as his development coach at Huddersfield Town.
Watson's playing career began at Newcastle United, where he came through the ranks at St James' Park alongside Clark.
After more than 200 appearances and seven years with Newcastle he joined Aston Villa in 1998, before going to link-up with Everton and West Brom.
He finished his playing career with Sheffield Wednesday in 2009 having completed more than 550 first team games.