Roberts, 51, came through the ranks at QPR and went on to make 146 Appearances between 1987 - 1998.BCFC
Roberts has a wealth of playing and coaching experience and is currently Wales national goalkeeper coach.
Due to Roberts appointment, Scott Bevan will now revert to his position as Blues Under-23s Goalkeeper Coach after overseeing the goalkeeper department for Karanka when he arrived as Head Coach.
Roberts, 51, came through the ranks at QPR and went on to make 146 Appearances between 1987 - 1998.
Injury ended his league career but Roberts established himself as Dagenham & Redbridge's all-time appearance record holder, amassing 482 games (and one goal) between 2000 - 2012.
Roberts helped the Daggers to promotion from the National League in 2007 and League Two Play-Off glory three years later.
Roberts was capped twice by Wales and on 30 occasions was back up to Neville Southall.
Holyhead-born Roberts became his country's goalkeeper coach in 2016.
Roberts' coaching career began while he was in non-league, combining his playing at Dagenham & Redbridge with duties at QPR.
He spent six years at QPR as first team goalkeeper coach after also working in their Academy, then he joined Arsenal where he committed almost eight years.
A move to Swansea came in 2015 where Roberts was first team goalkeeper coach and also interim first team coach during a three-year stay.
He left Swansea to join Chris Coleman, who drafted him into the Welsh coaching set up, in China two years ago at Hebei China Fortune.