Some football matches begin long before the referee blows the whistle.

They begin in conversations between supporters, in memories of famous victories, in old wounds that have never completely healed and in the quiet confidence that something special might be about to happen.

There is something almost impossible to explain about the feeling surrounding a huge derby. The anticipation builds gradually, the smallest piece of team news suddenly becomes headline material and supporters begin imagining every possible scenario.

For Celtic supporters, these occasions carry an even deeper meaning.

The green and white is not simply a colour. It represents generations of loyalty, tradition and memories passed from parents to children. It represents the nights when Celtic defied expectations, the afternoons when the club stood tallest and the moments that became part of the folklore supporters still talk about years later.

That history gives every Old Firm meeting an extra edge.

It is never merely about ninety minutes.

It is about pride.

It is about bragging rights.

It is about walking away knowing your side has stood above its biggest rival.

And ahead of Sunday’s enormous Premier Sports Cup quarter-final, Celtic supporters have suddenly been given something else to talk about.

Something potentially very important.

Something Rangers supporters may wish had arrived at a different time.

RANGERS’ INJURY LIST HAS CELTIC FANS SMILING

Rangers will welcome Celtic to Ibrox without several important players, and the timing could hardly be more awkward for Derek McInnes.

Youssef Chermiti remains sidelined with a long-term ACL injury.

Lawrence Shankland, the Rangers captain, is facing between three and four months out after suffering a hamstring tear.

Daisuke Yokota has undergone groin surgery and will also miss the contest.

Tuur Rommens remains unavailable despite beginning to run again.

Kosta Nedeljkovic is another concern, with a foot problem leaving him doubtful and unlikely to feature.

That is a substantial list.

And for Celtic supporters, it is difficult not to look at it and wonder whether Rangers have just been handed a rather unfortunate problem at precisely the wrong moment.

The Hoops will not need reminding that Old Firm matches are often decided by fine margins.

Having key players missing can be the difference between controlling those margins and losing them.

For McInnes, the biggest headache could come in attack.

Rangers have lost major options, meaning Bojan Miovski, Ryan Naderi and Kevin Kelsy could be required to carry more responsibility.

That is not an easy assignment.

Especially against Celtic.

Especially at this stage of a cup competition.

And especially when the entire stadium will be demanding a performance.

“The Rangers injury list may have opened the door for Celtic. Now the Hoops have to be ruthless enough to walk straight through it.”

THE PRESSURE HAS SHIFTED

This is where the psychology of the derby becomes fascinating.

Rangers will have the home crowd.

They will have the noise.

They will have the motivation of trying to defeat their biggest rivals.

But they will also know that their squad is not at full strength.

That creates pressure.

Celtic, meanwhile, can approach the contest knowing they have received encouraging news of their own.

Kieran Tierney is fully available after recovering from a thigh problem.

The Scotland international returned from the bench during the midweek victory over St Johnstone and is now ready for selection.

That is a major boost.

Tierney offers experience, aggression and quality.

He can defend.

He can attack.

He can provide width.

And he understands exactly what these fixtures mean.

Mika Baur is also expected to be fit after missing Friday training with a minor knock.

Martin O’Neill has confirmed that Baur should train on Saturday and is expected to be available.

So while Rangers are looking at who they have lost, Celtic can look at who they have available.

That contrast will not have escaped anyone.

CELTIC ARE ARRIVING WITH A PERFECT LEAGUE RECORD

Then comes the form.

Celtic have won all six of their Scottish Premiership matches this season.

Six games.

Six wins.

No league defeats.

No dropped points.

That is the sort of start that creates belief inside a dressing room.

The latest victory came against St Johnstone in midweek, when Celtic secured a 1-0 win.

The scoreline may not have been spectacular.

The message was.

Celtic are finding ways to win.

Rangers have also won their last four league matches, so there is no reason to suggest they will simply roll over.

But this is a different examination.

This is the Old Firm.

Form can disappear.

Confidence can become nerves.

One goal can transform everything.

That is why Celtic cannot become complacent.

ONE GOAL COULD CHANGE THE ENTIRE ATMOSPHERE

Ibrox will be packed.

Around 50,000 Rangers supporters are expected to create an atmosphere that will be relentless from the first minute.

There will be songs.

There will be noise.

There will be pressure on every Celtic touch.

Rangers will attempt to feed off it.

But Celtic can use that pressure against them.

Imagine the first 20 minutes passing without Rangers scoring.

Imagine Celtic growing into the game.

Imagine the Hoops finding the opening goal.

Suddenly, the atmosphere changes.

The crowd becomes anxious.

The Rangers players start feeling the weight of expectation.

Every missed chance becomes more significant.

Every misplaced pass becomes louder.

That is when Celtic could smell blood.

“Ibrox can be a weapon for Rangers, but if Celtic strike first, that same atmosphere could become the pressure that suffocates them.”

That possibility will surely be somewhere in O’Neill’s thinking.

CELTIC MUST ATTACK THE WEAKNESSES

There is no point pretending that Rangers’ injury situation guarantees anything.

It does not.

But it does give Celtic information.

It tells them where the opposition may lack depth.

It tells them which players could be carrying greater responsibility.

It tells them that the visitors must test Rangers repeatedly.

Celtic should make the Rangers defence work.

They should move the ball quickly.

They should attack spaces.

They should make the home side run.

And when chances arrive, they must be clinical.

This is not the afternoon for generosity.

It is not the afternoon for unnecessary mistakes.

And it certainly is not the afternoon for Celtic to allow Rangers to believe they are comfortable.