“WE HAD proved to ourselves we could beat Rangers and, in doing so, dismantled a psychological barrier. Jock was often quoted as saying that playing Rangers was just another game, but that was nonsense. No game was more important to him because he believed those games were a continual proving ground.”

Over half a century might separate the beginning of Jock Stein’s tenure and now but there is certainly still a ring of truth in those sentiments.

Plenty has changed of course, particularly in Govan, but one thing that hasn’t is when Glasgow’s big two square off it is still viewed as a proving ground for both clubs.

On Sunday, all Celtic proved was that they still have a way to go before they break through this particular psychological barrier.

That’s now seven Glasgow derbies without a win, stretching back almost two years to the 2019 League Cup final.

At Ibrox specifically, Sunday’s defeat made it four visits in a row without tasting victory at a venue that only a few years ago had become party central for Celtic fans to such an extent that Rangers reduced the away capacity to a measly 700 or so.

Coming into the game off the back of sealing Europa League group stage qualification against a talented AZ Alkmaar side, as well as comprehensive 6-0 wins over Dundee and St Mirren and a dominant 3-2 beating of Hearts, meant Celtic supporters had every right to believe now was the time to end their recent Ibrox hoodoo.

That doubtless makes the disappointment of another defeat harder to take – but it wasn’t all bad. Carl Starfelt had probably his best game in a Celtic jersey, while the rise and rise of Anthony Ralston continued unabated and Josip Juranovic coped well in a pressure-filled debut.

And there were chances. Odsonne Edouard’s 25th-minute sclaff as well as Kyogo Furuhashi’s two after the break immediately come to mind while, in the first half especially, there were passages of play that made it seem like the Hoops were relatively comfortable despite their hostile, home-fans-only surroundings.

On the flip side of that was the concession of another goal via a set-piece, a lack of real game-changing options to come off the bench and tactical decisions which did not pay off.

The silver lining is that all three of those problems are, to varying degrees, eminently fixable.

Celtic’s weakness at set-pieces last season was a thing. They were simply poor at defending corners and free-kicks. They conceded 12 goals from set-plays last term, the joint fourth-worst total in the league behind 10th-placed Ross County (18), relegated Kilmarnock (14) and newly-promoted Dundee United (13). 

So far this season the perception is that Celtic have improved slightly in that respect, although Filip Helander having the freedom of the Ibrox penalty area on Sunday may suggest otherwise.

Sure, training-ground work and video analysis might not be the same as hopping in a DeLorean, revving it up to 88mph and jumping back through time to change what happened but it can, theoretically, help to prevent it transpiring again.

“Anytime you concede a goal it is always disappointing,” as Celtic manager Ange Postecoglou said afterwards. “You go and analyse it at the end. It was a tight game.”

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Tactical decisions, too, can be recalibrated. Sometimes they just don’t pay off in a specific match. Postecoglou has already held his hands up that starting Kyogo wide left instead of central was going against what he himself felt was probably best and that he later brought on Tom Rogic for that reason.

"I thought Kyogo would be much more of a threat down the middle,” said Postecoglou. “To be honest, I think I should have started him there to begin with but with (James) Forrest out we are short in the wide areas at the moment so I had to start with him out wide on the left.

“I knew that, with his speed, getting Kyogo in the middle was going to cause them problems.''

It did cause them problems. Celtic’s best chance of the first half came from Kyogo out left, yes, but their two best chances of the second came from his movement creating havoc in central areas. That the attacking threat they appeared to carry in the final third increased exponentially after the positional shift too suggests maybe Postecoglou’s post-match assessment is correct. You live, you learn.

That comment about Forrest is just as important, though, and it ties into the squad depth issue as much as tactics.

Injuries are part and parcel of football – and I suspect will play a big part in how Celtic fare this season given the high-intensity style Postecoglou is implementing – but Sunday laid bare just how much a couple of knocks can hinder the Hoops.

Rangers, on the other hand, had no less than five players out due to Covid issues and yet still managed to field a team containing all but two of their first-choice XI.

That depth does not exist at Celtic, who were missing only Greg Taylor and Forrest from the pool of players considered bonafide first-teamers so far this season and yet the manager was forced to play a right-back on the left and did not feel like he could turn to the only striker on his bench, Albian Ajeti, even when the team were desperately seeking a goal.

That Juranovic acquitted himself well on his debut out-of-position at left-back is almost beside the point, although it does bode well for his future prospects at Parkhead.

Likewise, Ismaila Soro and Adam Montgomery played their parts as well as they could after coming on but their introductions were hardly inspiring. Rogic was the only real game-changer available in reserve for Postecoglou and in late August that surely constitutes a problem.

With only two days left in the summer transfer window time is running out for Celtic to strengthen the areas they need to. That Ryan Christie – himself out of contract in winter – was shifted into three different positions over the course of Sunday’s game to account for the lack of direct alternatives simply reinforces the point.

Currently, this squad probably has enough about it to see off the majority of opponents they will face domestically more often than not. The St Mirren, Hearts (the second time) and Dundee games demonstrated that. 

Where squad depth inevitably comes into it, however, is when Plan A isn’t really working.

It didn’t work well at Ibrox on Sunday but Celtic still constructed enough chances to win the game had Edouard had his shooting boots on or had Kyogo chosen to pass instead of going for goal. Such are the fine margins that decide whether a game is remembered fondly or not.

Against Rangers, Celtic had the chance to prove their recent upturn in form and results was more than just a purple patch. They didn’t quite do it but neither has that run of form and the culture Postecoglou is clearly building been undermined by one loss at Ibrox, proving ground though it may well still be.

How Celtic respond – as a club in the next two days and as a team in the coming months – will tell us if they’re ready to dismantle this new psychological barrier that seems to have arisen.

Oh, and that quote at the beginning? That was Billy McNeill. He knows a bit about proving yourself at Parkhead after all.