But the suspensions will do little to dampen what was another encouraging night at Windsor Park.
Hungary had piled the pressure on Northern Ireland by winning in Georgia earlier on Saturday, and Northern Ireland’s response sets up a showdown to top the group on Tuesday.
“We were aware that Hungary had won the game earlier and we’re in a great position,” O’Neill added.
“It would be great to win the group. It will be a tough, tough game but this is a brilliant game for us. It’s a great arena to play in.”
Having kept five clean sheets in as many matches, O’Neill is targeting completing the campaign without conceding.
If they can do that, they would not only win promotion but secure a play-off for Euro 2028 as a back-up should their qualifying group not go to plan.
“For a nation of our size, with our players at this stage of their careers, to have a chance to win the group and also to be playing Nations League A is a big achievement.
“I think we would probably be one of the smaller nations to play at Nations League A level since the start of the competition.
“We want to try to achieve that and we have a chance to do that on Tuesday night.”