Wright suffered a hamstring strain during Saturday's goalless draw at Brentford and will undergo a scan on Thursday to determine the extent of the damage.
Fellow left-back McNulty has made a remarkable recovery after having a kidney removed following a horrific collision in the match against Crewe in February.
McNulty would be a ready-made replacement for Wright, although the Seagulls do not want to rush him back so he will probably start on the bench with Andrew Whing filling in on the left.
Striker Gary Hart is Albion's only other absentee and will be out for another fortnight with a toe injury.
