The trio missed Saturday's 2-1 defeat to Leeds, while goalkeeper Jason Steele and striker Marvin Emnes played on despite suffering from the same illness.
Defender Rhys Williams has an outside chance of returning to the squad for the first time since damaging ankle ligaments in August. He has resumed light training.
Andy Halliday came off the bench against Leeds after recovering from a groin injury and could return to the starting XI.
Midfielders Julio Arca (toe) and Muzzy Carayol (knee) and striker Curtis Main (also knee) are close to returns from long-term injuries.