There is a telling moment in the oft-quoted Being Liverpool documentary that Brendan Rodgers was coerced into when he was the Anfield manager.

As Rodgers gathers the youth players involved in first-team training together after a pre-season session and beseeches them to improve their attitude, a truculent 17-year-old Raheem Sterling mutters ‘steady’ under his breath. It does not go down well.

The scene becomes reminiscent of the headmaster’s office with a dressing down and a stern warning delivered about the first flight home.

Read more: Neil Lennon can take over the reins at Celtic whenever Brendan Rodgers moves on

And yet you would be hard pressed to describe Rodgers as a disciplinarian.

On Sunday afternoon there was a rare glimpse of frustration as Kristoffer Ajer felt the full force of his ire when he was rolled by Alfredo Morelos in the early stages of Sunday’s game at Hampden but by and large Rodgers is considered and composed in language both bodily and verbally.

Indeed, the days of ranting and raving managers throwing boots or cups or whatever else comes to hand already seems reminiscent of a former era. Just as society has moved on, so has the culture of the dressing room.

But one perennial rule has never wavered; an odour of fear will not end well.

Footballers scent fear. They exploit vulnerability. Ask Ian Cathro, ask Graeme Murty.

So when Rangers chairman Dave King undermined his own manager last week with an ill-timed statement in the build-up to the weekend’s now infamous afternoon at Hampden he effectively threw his own man to the wolves.

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The implosion that followed with Lee Wallace and Kenny Miller was as predictable as it was damning.

No dressing room takes well to being humiliated on a football pitch. Rangers were soundly beaten on Sunday in a game that the statisticians will record as a 4-0 defeat but which observers will recall as 4 going on 44. Such was the lopsided nature of the affair that it would be a travesty to describe it as a contest.

Any student of history will eagerly regale willing listeners of the repetition of human error. And where Rangers’ dressing room was late afternoon on Sunday was where Celtic were in February 1999; indeed it wasn’t too far off where it was in October 2015 as Kris Commons let rip at Ronny Deila following a harrowing night in Norway.

There was a glimpse of petulance towards the Celtic bench from Leigh Griffiths towards the end of last season when the striker was irked at being subbed against Partick Thistle at Firhill. At the time the Scotland internationalist was the only fit forward at the club and was taken off as a sensible precaution with one eye on the Cup Final.

Read more: Neil Lennon can take over the reins at Celtic whenever Brendan Rodgers moves on

Rodgers was quick to defuse the situation – an arm was slung over the shoulder of the player as the TV cameras honed in – but ultimately if a team is winning and delivering trophies no-one gives much of a damn.

The currency held by coaches and managers comes not with an iron rule but with points on the table, with silverware in the cabinet. That alone is what marries the trust between the training ground and the manager’s office.

Players aren’t afraid of managers. What they are afraid of is losing their place as others make up ground behind them - indeed, as other teams romp off ahead of them.

Let no-one kid you; the measure of success is not just sitting on the cusp of a double treble but creating an environment where no-one wants to miss a thing.