Nottingham Forest forward Ward, who is currently on loan at Burton Albion, suffered a broken wrist during his side's Championship clash with Barnsley at the weekend and is expected to spend several weeks on the sidelines.
Dallas, meanwhile, has not featured since picking up a calf injury against San Marino during the last international break and will continue his recovery at Leeds United.
Manager Michael O'Neill has opted not to call up any replacements for the injured duo, deciding instead to stick with a 23-man squad.
Northern Ireland currently sit third in Group C, three points adrift of Azerbaijan heading into Friday's match in Belfast.
O'Neill's side will then host Croatia in a home friendly in their final match of 2016.