Ange Postecoglou has said and demonstrated it over and over again. He will not yield from his principles and beliefs.

Under him, Celtic will go out to hurt the opposition and win games, home and away.

This attacking strategy has been their big strength this season against the relentless domestic grind of the low block largely adopted by Premiership clubs.

It is also the chink of light in their armour.

There is no Plan B for the Aussie coach. It appears his alternative is to see Plan A performed better or bust. A true believer in his attacking philosophy, it’s clearly not something he puts on for effect.

Because of this, Giovanni van Bronckhorst goes into the match at Ibrox on Sunday knowing exactly how Celtic are set up to play. There will be no surprises.

He knows they will start like a whirlwind. He knows they will look to create overloads wide and send low crosses into the box. He knows their early press will be viciously intense. And yet, he will also know how to combat each of these tactics.

As The Rangers Review have investigated here, watching Norwegian side Bodo Glimt largely control Celtic across 180 minutes in their Europa Conference League tie offers a blueprint that must be learned from, especially without the ball.

If van Bronckhorst has shown one thing since arriving as manager in November, it’s that he’s no ideologue with a fixed notion of how to achieve success. He has the capability to shape a different plan as a game is in motion. Few managers are capable of such clear judgement in the heat of the battle and yet Dortmund and Red Star stand as testament to a clear-minded outlook unimpeded by the pressure caused by a ticking clock and passionate crowd. While Steven Gerrard, like Postecoglou, had a game model he wouldn’t deviate from, the Dutchman is much more of a tactical tinkerer and pragmatist.

It’s clear from his early work at Rangers and his time at Feyenoord he likes a traditional 4-3-3 as a starting point but that hasn’t stopped him using a back three, adopting a lopsided shape to allow James Tavernier into more attacking areas or even using John Lundstram in a hybrid position that sees him move between defence and midfield depending on the state of the game.

READ MORE: How Rangers' three-man defence can help avoid repeat Celtic nightmare

This should give fans of the Ibrox club confidence their manager has the flexibility to find solutions to the problems Postecoglou’s team pose.

That said, the last match between the sides was undoubtedly the worst 45 minutes we have seen from Rangers in the four years since Gerrard arrived to revolutionise the squad. It's to the manager's credit that he made sweeping changes at half-time that totally changed the complexion of the game with Rangers the marginally better side in the second half. Armed with the additional knowledge of seeing Celtic up close, van Bronckhorst should be able to affect more change from the start this time.

But there will be more to this game than mere strategy. Legendary playwright Anton Chekhov once said: “Knowledge is of no value unless you put it into practice.”

At Parkhead, Celtic earned their right to play with a perfect application of the basics that Rangers simply didn’t match. While tactics are essential to modern elite football, they don’t make up for a failure to match opposition intensity, to track runners properly or to bust a gut to help a struggling teammate.

These aspects are the foundation stone of any Old Firm win and Rangers can’t allow their opponents to beat them for attitude on a second occasion. It’s an old cliché that you have to ‘earn the right’ to play your football, but it stands because it’s often a truism.

The game looks certain to be highly contested but the Ibrox side have the advantage of knowing what their opponent will do. Celtic do not have that luxury.

There will be few excuses if they don’t use this to their advantage.