It doesn't matter how many teams Celtic boss Ange Postecoglou says it. There are still some people out there involved in football - and who really should know better - who are not listening.

Read his lips: "I won't change my approach." It's five simple words, isn't it? Yet so many football people struggle to comprehend it. Why is that?

The Aussie has also said on the record: "During my whole career, people keep telling me I need to adjust my approach and temper my aggression. What I have tried to explain to people is that I don't do this to prove something. Oh, I love this kind of football. I do this because it's successful. I know that's the way to success. I've done pretty well just sticking to it, to be fair, so I'll just keep going."

The ex-Socceroos coach plays the Celtic way - or "our brand of football" as he likes to call it. Many will have their opinions on it.

Those voices reached something of a crescendo after the Hoops brought the curtain down on their Champions League Group F campaign with a 5-1 defeat in the Santiago Bernabeu to Real Madrid.

Rangers, RB Leipzig or Los Blancos? It doesn't matter to the Aussie. His approach stays the same and the Parkhead side will continue to play that way.

Here's the thing. After the Bernabeu bashing pundits, ex-players and commentators alike were all lining up to have a subtle go at Postecoglou.

There was a certain word banded about after the loss to the European champions. That word was 'naive'. 

Former Liverpool and Real Madrid winger Steve McManaman kicked it all off when he said on BT Sport: "Celtic have to be a little bit more savvy in Europe, don't they? They are too easy to play against. They were a little bit naive.

"Yes, they had nothing to play for and they can go and do something tonight but once you get to 2-0 or 3-0, you always start looking at conceding and that's not what you don't want to happen at times.

"But I thought it was a very enjoyable game and hopefully these boys, the Celtic lads will have learned from this experience, they will have enjoyed it and want plenty more of it in the near future."

Then ex-Celtic striker Chris Sutton used the same term on social media, albeit in a slightly more praising manner.

"Tough night," he posted. "Unforgiving but got to stick with it. You could say there's a naivety about this Celtic team when still throwing men forward at three and four-nil down but that's the Ange process and Celtic miss some huge chances... I think Celtic will be better for this experience.

"Postecoglou is trying to change a mindset here. I like what he's trying to do, and the message he's trying to send."

Then there's former Republic of Ireland and Manchester City defender Richard Dunne. He wants the Scottish champions to abandon their principles altogether and adapt and learn a new style under the manager, especially when they are playing at the Champions League level.

He told Virgin Media Sport: "For Celtic to progress, they have to realise the level that they are at compared to the real top sides in Europe. Maybe they have to go and soak up a bit of pressure to try and defend as a team rather than turning games into basketball games with this end-to-end all the time. The bigger sides will do what Real Madrid did to them.

"For the manager, it's a case of 'this was a learning step' this season and now they know they can't do this again. Inevitably they'll get a lot of supporters, applause and plaudits for that stuff, but they won't get through the group. They've done it their way this season but now they have to adjust from the league into the Champions League next year."

Celtic Way:

Who says Celtic have to adjust? Basketball games? You would think the Hoops were a basket-case for trying to stick to a gameplan the way some pundits were reacting.

Have they not been paying attention to what the former Yokohama F Marinos manager has been saying since he waltzed through the door last June? Evidently not.

Surely the Parkhead boss knows which style, approach and philosophy suit his team and his players best. Canvass any supporter and they would opt, for want of a better phrase, 'Ange-ball'.

The team were competing at the elite level of club football for the first time in five years. Postecoglou had a squad consisting of players who were taking their Champions League bow in the competition.

Over two games against the current Champions League holders, it is not a stretch to say that Celtic could have scored four or five goals. They even blew a golden opportunity from 12 yards, for goodness sake. Ironically, the Hoops' penalty in the Bernabeu was earned by the team going on the front foot after being 2-0 down.

Would parking the bus or a more pragmatic approach yield a similar outcome? As the 57-year-old was quick to point out: "I've never owned a bus, mate!"

There are even supporters out there who, despite the Champions League results, think that it is a wonderful time to be alive. They are adamant that the way the team is playing has been a breath of fresh air and an absolute joy to watch, as well as the fact that it is only a matter of time before he and the team crack it in Europe.

After all, the Scottish champions were fiercely competitive in every match of this season's group stages. They were undone on Wednesday night by what the Australian called 'a fantastic football team'. There is no shame or disgrace in that. Los Blancos could do what they did to the Bhoys to any opposition on earth. Yet the Parkhead side still had their moments in one of the biggest footballing arenas in the world.

If Celtic can win the Scottish Premiership title for the second year running, then they will gain automatic access to the group stages once again. That will be the time for judgement calls and to see whether Postecoglou's men are better off for having had the Champions League adventure and experience this season.

The manager has every confidence and faith in his players to turn his style of football into success on the European stage.

After full-time, he said: "I never fear the worst because we're still trying to play. I'm really proud of our players. I mean, we've lost 5-1, and we understand that against a fantastic football team, but the players never stopped trying to play. They created, I don't know how many chances, but Thibaut Courtois was outstanding.

"So I don't fear anything with this group of players. It took an enormous effort tonight for our boys to try and match it with one of the best football teams in the world. But if we go in there with that intent every week, we will be hard to stop."

If you haven't got it by now, then maybe you never will. The Aussie is not talking about being hard to stop domestically, either. He includes the Champions League in that statement. it's not Postecoglou or Celtic's mindset that needs to change here.

If you weren't listening or paying attention to his post-match Madrid interview or anything that he has said up until this point, then it really does beggar the question: who is really being naive here?