O’Neill watched the highlights on Saturday night when a change of formation helped England come from two goals down to record a 3-2 friendly victory in Berlin.
That result, coupled with Republic of Ireland’s qualification win over them in October, will have given encouragement to a Northern Irish side that are in Germany’s group in France this summer.
And O’Neill insists he must do whatever he can to convince his players Joachim Low’s team are fallible ahead of their June 21 clash in Paris.
“I don’t think we would maybe approach it the way England would approach it,” O’Neill revealed.
“Every team has frailties and I think England exposed that to an extent. It was interesting that the starting line-up of Germany had only five that started in the World Cup final. There’s been quite a transition in their team and squad. Speaking to different people, there’s certain areas they are concerned about.
“I’m not going to say too much because his (Low’s) options are pretty good!
“There’s no point in us telling our players, ‘These guys are brilliant, we’re never going to beat them’. If there aren’t frailties there, we will make them up and we’ll tell the players that!
“I haven’t watched the (England) game in any great detail. Even in qualification, you see the Republic of Ireland took four points off Germany, Scotland were narrowly beaten at home and away.
“There’s maybe a combination of a hangover from the World Cup and a bit of transition in their team as well. But we’re under no illusions; it’s going to be as difficult a game as we can possibly expect.”
Speaking before facing Slovenia in Belfast tonight, O’Neill also responded to the subject of Troy Deeney’s eligibility, which came up after the Watford striker was quizzed about his international future. Deeney had said “we are just confirming the Northern Ireland thing at the moment” on Saturday, three years after O’Neill confirmed he could not be called up because it was his great grandfather, rather than his grandfather, who had the Northern Irish heritage.
“You could dress this up and tell half truths, but the reality is nothing has changed,” O’Neill confirmed.
“I spoke with Troy about four years ago, not long after I took the job. I was alerted to Troy’s potential eligibility, and I spoke to the player and had him watched. We were informed that the eligibility wasn’t there, so we didn’t pursue it any further.
“So the idea that we are suddenly speaking again is strange. We haven’t spoken since four years ago. Saturday’s news prompted a few texts and tweets, but it is news to me, as it has been to everyone else.”
Asked whether it was worth contacting Deeney to revisit the idea, O’Neill added: “I don’t think there is any point — unless the situation has changed. Maybe his granny has moved up a generation! There is very little I can do about that. There are conversations we could have, but it is not high on my agenda. My focus is on the players I have here.”