Seven players have been told by manager Gianfranco Zola that they will be offered new contracts, or have their options taken up: Connal Trueman, Jake Weaver, Wes Harding, Dominic Bernard, Wes McDonald, Beryly Lubala and Kyle McFarlane.
Four are to be released at the season's end, when their current contracts are due to expire: Charlee Adams (pictured), Charlie Cooper, George O'Neill and Logan Kwiecien.
A decision on Daniel Cleary's future is to be made at a later date.
Goalkeepers Trueman and Weaver have often shared duties for the Under-23s, with Trueman also called up to the First Team bench when Tomasz Kuszczak was injured.
Defender Harding is the current Under-23s captain, while fellow defender Bernard was on the verge of a breakthrough until he sustained an injury that has hampered his campaign.
Forward Wes McDonald is in a rich vein of form at present and has impressed month on month for the Development Squad, and attacker Beryly Lubala brings ability and versatility to the side.
Like Bernard, Blues have shown their faith in forward Kyle McFarlane, who was impressing before he was struck down by injury.
Of those released, Adams has First Team experience. He made his senior league starting debut on the last day of last season at Cardiff City and the playmaker was loaned to Kilmarnock for the first six months of this campaign.
Midfield Cooper, son of former Blues player Mark, is currently on his second loan spell at Forest Green Rovers, but like striker O'Neill has been unable to break into the First Team reckoning.
Defender Kwiecien was signed on a six-month contract by Blues from Beaconsfield after a successful trial period, along with winger Ollie McCoy, who remains contracted until 2018.
Blues had already informed Koby Arthur and Noe Baba that their deals would not be renewed, while third year Scholar Josh Tibbetts is also to be released this summer.