Forward Bunn (hamstring) and left-back Robinson (knee) were both forced out of Saturday’s draw at Birmingham and will play no part.
Striker Nahki Wells is not expected to return from a shoulder injury that has ruled him out of the last four matches, but hopes to be back in contention for Saturday’s home game against Fulham.
Defender David Edgar, on loan from Birmingham, returns to contention after being unable face his parent club at the weekend, while boss Chris Powell has no other new injury concerns.
Norwich have no new injury concerns, with midfielder Alex Tettey fine after suffering a headache when clashing heads with Jamie Hanson during Saturday’s 1-1 draw at home to Derby.
Belgian midfielder Vadis Ojidja-Ofoe was not on the bench against the Rams but will travel with the squad, as should young striker Jamar Loza.
He was not included in the Under-21 squad for Monday’s match at Tottenham but defender Ryan Bennett did feature as he continues his recovery from a hamstring injury.
Winger Nathan Redmond has been on the bench for the last two games, seeing only 12 minutes of action, and will be looking for a return to the starting line-up.