The 24-year-old has only made four appearances since being signed by Brian Little in June 2001, and his only sight of first team football has been from loan spells at Lincoln and Telford.
He hasn't figured in Peter Taylor's plans, and so has been released on a free transfer despite having six months left to run on his contract. He follows Ben Petty and Mike Price, who have also had their contracts terminated in recent weeks.
Bloomer is now training with Grimsby Town - the club City signed him from a year and a half ago - while he looks for a new team.