The Shakers have signed the rookie Blackpool defender on a six-month loan deal after losing centre-back Mark Hughes to a hamstring injury which is expected to sideline him for around six weeks.
Eastham, a product of the Seasiders' youth system, goes straight into the squad at The Valley and will be joined by Andy Bishop.
The striker was rested for Tuesday's Carling Cup home defeat against Leicester, while fellow forward Mark Cullen should be fit after a recurrence of a hamstring strain. Midfielder Steven Schumacher is still sidelined through injury but Barker has no other concerns.
Striker Benson, who marked his first start this term with a goal in the 2-1 Valley win, has fractured a finger.
Boss Chris Powell made 11 changes on Tuesday night so the likes of goalkeeper Rob Elliot, defenders Matthew Taylor and Michael Morrison, midfielders Johnnie Jackson and Danny Hollands along with strike duo Paul Hayes and Bradley Wright-Phillips will be expected to return.
But Powell has some welcome selection dilemmas with full-back Andy Hughes, midfielder Bradley Pritchard and winger Danny Green catching the eye.