Midfielder Smith missed Tuesday's defeat by Gillingham after he was sent off at Peterborough on Saturday.
He will take Hartley's place in the squad after the defender collected a fifth yellow card in midweek.
Striker Darius Charles is not expected back until the new year with the ankle ligament damage which has sidelined him since August and centre-half Ben Chorely is still building up his fitness after groin and thigh problems.
- Sports & Recreation
- Darius Charles