Despite featuring in recent friendlies, following talks with manager Adam Hinshelwood the 24-year-old has decided to move on in order to search for more playing time.
Barker joined the Reds in February 2018 after leaving Brighton & Hove Albion after injury ended his hopes of an extended stay with the Albion.
His five and a half year spell with the club comes to end having made a total of 154 appearances in a Red shirt, scoring 8 times.
Sometimes deployed in as an auxiliary defender his versatility and consistency has contributed massively to the club’s success during his time and everyone associated with the club wishes him all the best for the future.