While the Black Cats are without leading goalscorer Steven Fletcher as well as captain Lee Cattermole through injury, O'Neill remains confident ahead of the game.
"You have to do it, you have to overcome odds that sometimes seem as if they are stacked against you," he said.
"There is a lot of spirit in the dressing room and that spirit alone might wrest a couple of points.
"Anyone coming in and telling you they are completely nerveless, I am not so sure that would be the case.
"You have to have some sort of nervousness - but you have to be able to deal with that, take care of it and not let it affect your game.
"From that viewpoint, yes, I think nerves and tension all become a part of it, but it's something you shouldn't be subjecting yourself to every single minute."
With Fletcher and Cattermole ruled out for the remainder of the season, O'Neill remains calm, adding: "I am not overly worried about the clamour. What you try to do is put out a side to win some games.
"We have used Steven on his own there for most of the season, Sessegnon playing in behind him.
"With Steven out now, we will have to make some sort of adjustments, but we will see how we go."