As the pre-match teamsheet arrived, an unusual buzz zipped around the Ibrox press box as small groups gathered together in an attempt to decipher what had arrived before them.

It resembled more of a puzzle than a line-up.

Had Rangers moved to a back three?

Was John Lundstram about to find himself in the middle of the back four?

The possibilities that sprung forth from the unusual selection of James Tavernier, Calvin Bassey and Nathan Patterson in the same starting XI were myriad.

A less discussed option was the potential for Tavernier at centre-half but as the teams trotted out into a deathly still cold and took up their places ahead of kick-off it became clear that was what we were about to witness – the captain as a makeshift central defender.

It was an innovation that was to last just three shaky minutes.

A clearly agitated Giovanni van Bronckhorst seemed to be gesticulating and barking at his defenders but what looked like upset was later explained clearly by the manager as he revealed he had set the team up for two eventualities and when Dundee United had shifted formation, so too did Rangers.

The quick solution was adopted in moving Patterson to left-back and shifting Bassey in one and suddenly things looked far more familiar.

And yet, while it may have stabilised some shaky foundations, it did nothing to spark his team to life.

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The descending mist that slowly engulfed the pitch gave the match an ethereal quality entirely in keeping with Rangers’ ghostly first-half performance.

Dundee United offered little in an attacking sense but were well organised without the ball and drilled with a level of precision that offered clear evidence of Tam Courts' coaching nous.

Declan Glass and Nicky Clark became a front two without the ball and brilliantly cut off the passing lanes from Goldson and Bassey into midfield. With Lundstram as the pivot, a player less comfortable taking the ball in tight situations, Rangers looked laboured in the build-up and created little of note.

GVB moved to address this by bringing Kamara back and pushing Lundstram forward, but even the press-resistant Finn struggled to get on the ball such was the intensity of the duo’s running.

The move at half-time to switch out the ineffective Lundstram came as no surprise but it was yet more evidence that van Bronckhorst is a pragmatist who adapts to the evidence unfolding in front of his eyes.

Certainly not an idealogue, the Dutchman shows signs of tactical flexibility that is already marking him out.

The introduction of Scott Wright in place of Lundstram made a huge difference as the team looked much comfortable in the second half. With Ianis Hagi also looking more comfortable in the middle of the pitch than as a wide-man they started slowly but eventually found more of a rhythm and wore United down.

When the penalty came the pressure had been building for some time. And not just on Charlie Mulgrew and co. Inside Ibrox there was a tension in the air, the fans only too aware of what dropping points might mean in allowing Celtic an inch in the title race.

That pressure, the channelled intensity of 49,000 souls, fell on the shoulders of James Tavernier as he stepped up to take the kick. He didn’t disappoint, blasting the ball into the corner with a ferocity that gave Trevor Carson no chance of protecting his team’s zero.

His manager summed up his confidence in his skipper after the game saying: “You put Tavernier behind the ball, then you know he’s going to score.”

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It was a moment of release after the tension that had gone before and the stadium came alive with a roar that shook the old ground.

And suddenly Rangers were playing with freedom again and looking consistently dangerous.

Morelos was denied a deftly finished goal by an offside flag and Hagi missed a good opportunity that summed up an afternoon where little went right, despite being surprisingly awarded the sponsor’s man of the match.

It was a decision that sent the stadium into a collective burp of ‘What?’ but to be fair to the Romanian, he battled away gamely throughout and never hid from his creative duties, even when things failed to come off.

But nothing could take the shine from an important three points.

Rangers had survived the first poor performance of the manager’s era but found a way to win in a game that might have proved more punishing if changes hadn’t been made.

It remains early days in the van Bronckhorst tenure but the Dutchman is already showing an adaptability in his tactical tinkering that suggests this marriage between club and manager will be a fruitful one.