The heart sinks because the head knows better
It will require a strong constitution to get through the next seven days where Rangers and Celtic are concerned.
The Old Firm in Europe will throw up a test of resilience, concentration and fortitude when they play AIK and Legia Warsaw on Thursday night.
Neither is absolutely guaranteed to qualify for the group stages of the Europa League. Each is vulnerable while juggling domestic commitments with continental considerations.
Celtic's two goal lead from the first leg against the Swedes looks comforting but defence will be a key area while they attempt to protect their advantage in Stockholm.
Neil Lennon spoke about "psychological fatigue" in the immediate aftermath of the league win over Hearts on Sunday, but tired minds will simply have to be overcome by an indomitable spirit on Thursday.
Or else.
Rangers have home advantage, minus three thousand empty seats that could have been occupied by their fans had it not been for sectarian singing in an earlier round of the competition, but also a nagging doubt for company.
A score draw puts the Poles through at Rangers' expense and nothing can be taken for granted.
The empty seats are a nonsense and for this reason. The scorer of Rangers' winning goal against St. Mirren on Sunday then made the sign of the cross in gratitude.
Rangers are hundreds of thousands of pounds out of pocket by virtue of a UEFA sanction imposed because some of their supporters recoil at that public demonstration of religious adherence.
It's so ironic a situation you wouldn't know where to start, would you?
Well, let's begin with next Sunday at Ibrox.
The heart sinks in advance because the head knows what is coming next.
What will happen on the park represents no problem at all. Both Rangers and Celtic are rich in talent and capable of providing an outstanding match.
For the first time in eight years I would venture that Steven Gerrard's side are favourites to beat Celtic.
Neil Lennon's area of vulnerability is at the back. Can he trust Christopher Jullien and Boli Bolingoli at Ibrox?
Alfredo Morelos has got to score his first goal against Celtic at some point and this weekend looks like his best bet.
The case for Celtic is made by Odsonne Edouard's habit of doing well in this fixture and the assorted talents of Callum McGregor, James Forrest, Mikey Johnston and Ryan Christie.
The imponderables are what happens in the wake of the European ties.
If both clubs qualify for the group stages then honours are even.
If one does and one doesn't, then there could be a residual effect where confidence and morale are concerned.
It's a football match, anything can happen.
What makes the heart sink is the certain knowledge that the air will crackle with the sound of offensive songs.
All of the fine words which have been spoken since UEFA's punishment for Rangers was announced will be forgotten.
The ground will reverberate to the sound of the songs which created the disciplinary problem in the first place and the remainder of the week will be taken up with recriminations, protestations and the demonstration of the fact that, when it comes to Rangers and Celtic, there is always more that divides them than will ever unite them.
The detestation they have for one another is ingrained and immovable.
Those who must indulge in anti-social behaviour are that way because they want to be that way.
It is a lifestyle choice.
In his private moments, Steven Gerrard must be taken aback by the environment he has entered while doing a first class job of turning round the football department at his club.
One day after he's gone somewhere else, grounds all over this country will be closed in part or in full as a consequence of the inability to quell crowd misbehaviour.
We're already on the slippery slope because the movement for change can't quite gather sufficient momentum to turn things round.
One Celtic supporter can be evicted from the ground after his fellow fans insisted on his removal following an object that was thrown on to the park on Sunday.
But it will require a lot more than one isolated incident of self policing to alter our damaged world of Scottish football.
Next Sunday will prove that