Their Boxing Day defeat at Fleetwood means the Shrimpers have won one of their last six games as they linger in mid-table.
Strike duo Jack Redshaw and Lewis Alessandra both came off the bench in that fixture and could be handed a starting place.
Bentley's side have managed just two goals in their last four outings and he may opt to rotate his attacking options.
Richard Brodie is most likely to drop out with fit-again Kevin Ellison still trying to regain his form after a recent return.
Midfielder Joe McGee is also pushing for inclusion against the Spireites having been on the fringes in recent weeks.