There are no government assessments to chart the damage a game of football can have on the health of its inhabitants but there is a suspicion that there may be a few moments of high anxiety for Celtic fans this season.

Palpitations are all well and good when they are coming at one end of the pitch but there is a feeling that the current set-up may well offer a steep incline in blood pressure when confronted with teams of some attacking repute.

Still, while it wasn’t all pretty in the Netherlands there was an argument that Celtic perhaps showed a different side to them last night.

Granted, it was a sight that anyone who has watched them in a European context would recognise given the gifts they offered which have made them hospitable guests on their Continental travels in recent years.

But in the last few weeks, as optimism has grown with the domestic slayings that Ange Postecoglou’s side have dished out, there hasn’t been much to assess about the current side when they are thrown into moments of adversity.

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That they steadied the ship against Alkmaar just as they were threatening to be swept away in a self-destructive tide suggested that maybe there is a little more mental steel than might have been there just a few weeks ago. Still, they diced with death through individual errors, a common narrative that underpinned much of last season.

The arrival of Odsonne Edouard helped enormously in the second period but there are few who would argue that any of it made for comfortable viewing. That they have come on in recent weeks is inarguable but a sober assessment would continue to point to the achilles heel of defensive vulnerability.

And with the days now ticking down to the closure of the transfer window it will be interesting to note where Celtic stand on the other side it.

Carl Starfelt has had a torrid start to his career at the club and has little credit in the bank when it comes to defending the own-goal. Christopher Jullien’s return ought to help Celtic in a defensive sense but there is a clear need for at least one other centre-half to come in.

Of equal intrigue is the situation of Ryan Christie and Edouard. The danger as the window draws to a close, of course, is that players go out without time to deliver a replacement.

The proximity to the window closing and the game at Ibrox shines a light again on club infrastructure.

Without a head of recruitment in place there are obvious question marks about who is making such decisions.

Certainly, Ange Postecoglou’s immediate sights now will be on Ibrox. Both sides go into the opening derby of the season on the back of edgy European performances.

They will matter little in the context of progression into the group stages of the Europa League but may have a bearing in how Sunday’s game plays out.

Who holds their nerve may well be the team who prevails.