Celtic's preparations for their opening Europa League group game against Real Betis were rocked by an injury to captain Callum McGregor.

Winger Liel Abada's unavailability due to Yom Kippur and the myriad injuries already damaging the squad mean manager Ange Postecoglou has some serious selection choices to make for the match in Seville on Thursday (5.45pm).

Recent signing Giorgos Giakoumakis has also been deemed not ready for first-team action yet while Kyogo Furuhashi and James Forrest remain out and Greg Taylor's shoulder problem will require surgery.

On the plus side, Anthony Ralston is back and could take up the right-back slot as Celtic seek to bust a hoodoo by winning in Spain for the time competitively.

Here, we take a closer look at Postecolou's media comments ahead of the game.

First on the agenda was the captain's injury as well as the squad depth issue in general, with Postecoglou telling his pre-match press conference: "It’s not great for us because Cal’s obviously a very influential player for us. We’re going through a period like that at the moment where we’re getting some significant outs (players missing games) but it’s kind of been the state of play since I got here.

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“We’ve been in a constant state of flux and not been able to settle. I see that as an opportunity for us to build resilience through this period and just keep going with what we've been doing and playing our football. If we can get through these periods without shifting from the kind of team we want to be, then it’s going to make us even stronger once we get everyone back.

"There's no football team, player or coach in the world who doesn't want to win. That's not what makes it unique - from my perspective, it's about who we want to be and how we want to portray ourselves as individuals and a team. What kind of team do we want to be? For some people that's a bit too grandiose, I get that, but that's my way of coaching. We talk about that to the players on a daily basis. There's no major shift in what I'm telling them."

Apart from the obvious point that McGregor's absence is a massive blow and there are still squad depth issues, the biggest takeaway from this is that Postecoglou is making it clear to everyone - journalists, fans, players, the opposition - that the building blocks he has been putting in place will not crumble just because of injuries. 

The way Postecoglou wants this team to play has been clear from the day he took the job. Plenty advised him to opt for a more pragmatic, defensive approach when Celtic seemed to be struggling a little early on in his tenure but the manager has full belief in what he is doing and will expect his players to have the same.

That does not mean it's simply going to be as-you-were against Betis. The opposition is undoubtedly a step up in class and the players Celtic will be missing are crucial to the style he wants to see.

Rather, it is now incumbent upon those selected to show they have the belief to keep attempting to play in the manner Postecoglou has been trying to instil in them. After all, if they don't do it under pressure, when the chips are down as they say, then has it really been instilled enough? That's the resilience he wants to see tomorrow, and in the next few weeks, as injuries take their toll.

On the opposition and expectations, Postecoglou said: "We had somebody watch them watch play on Monday. We’ve got all the information we need on them. They’ve brought in one or two but they’re a pretty settled team. They had a fantastic season last year and they’ve got an outstanding manager but they’re the type of opposition we want to test ourselves against.

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“It’s why we were so pleased to get into this group stage because we knew we’d get some pretty exciting fixtures. We want to enjoy it but we’ll only do that if we have an impact. By that I mean can we play our football against some quality opposition home and away?

“We’ll hopefully be involved in some special nights but I want the enjoyment to come from us believing in something - and that something for us is about the kind of football team we want to be.

“I don’t want us to be fearful or hesitant. To truly take in an experience, I’ve always felt that you need to give all of yourself and believe in something and, usually, you come away having lived that experience to its fullest"."

Again it is clear from Postecoglou's choice of words that he relishes the chance to see his players demonstrate what they've learned by applying it on the biggest stage they can at the moment. Group E is arguably the toughest in the competition and any points garnered will have to be fought for gallantly.

The match marks a return to Seville for the club over 18 years on from competing in the Uefa Cup final against FC Porto. Postecolgou nodded to the importance the city has come to have in the hearts of Celtic supporters despite the final defeat that day.

He said: "There’s obviously a historical significance with us going back to Seville. When you walk around Celtic Park, there are images everywhere of Martin O’Neill or our fans enjoying the past experience on that day in Seville and in European competition, so of course that has an impact.

"It would have been great to have some travelling support across there because it's a journey you want to share with your supporters but, irrespective, you understand the historical significance but it also motivates you to make your own stamp. That’s what I keep saying to this team – they’ve got an opportunity to create their own moments in this great football club's history and create nights that hopefully can be talked about by future generations."

The impression of Postecoglou so far is largely that of a man who 'gets it'. He does that reputation no harm at all here, not only by referencing the halcyon days of Martin O'Neill but by setting out his stall to add some European memories of his own during his stay in Glasgow.

How he would dearly love it if the first of those was an against-the-odds, duck-busting victory in Seville on Thursday.