TWTD understands U23s quartet Levi Andoh, Bailey Clements (pictured), Tommy Hughes and Ben Morris have all been offered the chance to remain with the Blues for 2021/22.
All four are out of contract this summer but with Town having options to keep them for a further season.
Amsterdam-born right-back or central defender Andoh, 21, joined the Blues in January 2020 and made what's so far his only senior appearance in the Papa John’s Trophy tie at Crawley last November.
Left-back or centre-half Clements, 20, came through the academy and played his only first-team game in the Carabao Cup tie at Luton in August 2019.
Midfielder Hughes missed virtually all of 2020/21 through injury having made his first senior appearances in the Leasing.com Trophy and FA Cup the previous season.
Striker Morris suffered his second cruciate knee ligament injury in Augusts last year and was sidelined for the whole of the campaign having only returned from his previous injury late the season before. Morris, 21, has made first-team start and three sub appearances.
As previously reported, midfielder Liam Gibbs has been offered a new contract which he is still to sign with his current terms not including an option for an additional year.