Sam Vokes, on loan from Wolves, has partnered Jermaine Beckford in recent weeks, but he and Leicester winger Max Gradel are both cup-tied, while Tresor Kandol starts a three-game ban after accepting a charge of violent conduct.
That leaves American Mike Grella and Enoch Showunmi to vie for a place alongside Beckford unless Becchio recovers in time for the tie, which will be the first game screened live by the Football Association on their website, www.thefa.com.
Grayson is not expected to make too many changes after his side's two successive 4-0 wins, but Neil Kilkenny is pushing for a recall after impressing as a second-half substitute against Yeovil.
Goalkeeper Shane Higgs (thigh), Ben Parker, Andy Robinson (both hamstring) and Rui Marques (Achilles) have struggled with injury in recent weeks.
Kick-off is at 5.15pm.