Northern Ireland lost 2-1 in the opening Nations League match against Bosnia & Herzegovina, a game that they dominated, and they will be looking to bounce back.
"It gives me an opportunity to look at some aspects of it. But were not in a position where we can just change nine players," O'Neill said.
"To do that we'd need to ask players to play out of position, and when you bring players in you want to give them the best chance to do well, so it's important to put them into a team which is cohesive and as strong as possible.
"There will be changes but its not just a case of starting the players who didnt play on Saturday. It's important that the lads get minutes. If I do make a change it will not be related to performance. "