Morgan Fox, who has deputised for Rhoys Wiggins in the last two games against Bolton and Sheffield Wednesday, has signed a deal that will keep him at The Valley until the summer of 2017.
Chelmsford born Fox will be 21 in September and has been capped at Under-21 level by Wales this season.
He played seven games on loan at Notts County earlier in the season and has waited patiently for his chance at The Valley.
Fox could have been bloodied last season, when both Wiggins and Cedric Evina were injured, but then manager, Chris Powell, opted to bring in Southampton’s left-footed centre-back, Dan Seaborne, as cover.
19-year-old, Dillon Phillips, agreed a two-year deal and has signed a contract that runs until the summer of 2016.
The Dagenham born stopper has made the occasional appearance on the bench recently but is still waiting to make his senior debut.
Nick Pope’s loan stint at York opened the door for Phillips during Yohann Thuram-Ulien’s absence.