Tomorrow night has the potential to be huge for Kristoffer Ajer.

I have to say that I don’t think the kid has done too much wrong since breaking into the Celtic first-team around Christmas time last season but this next month could be a huge test for him.

This is where we can see just how he can cope with the pressure of playing at Celtic in games that we all know are fraught because of what rests on them.

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There is no question that Brendan Rodgers has a massive headache for tomorrow night at the back. I thought Jozo Simunovic was dreadfully naïve with the tackle that saw him sent off and it has really put Celtic in a difficult position.

I know that sometimes at the start of the season you can be out with your timing and what not but the lad was going nowhere and there was really no need to rush in the way he did. It is done now but it will have been hanging over Brendan all week.

He has opted not to recall Dedryck Boyata and although Mikael Lustig is back in the squad I honestly feel that this game against Rosenborg could come too quickly for him. He’ll be fit but he’s had a fortnight off and I just think that he will need some training to get back into things.

The sports science guys will have him thoroughly checked out and it might be a case of needs must simply to try and get through the game.

I actually covered Costa Rica’s game against Switzerland in the group stages of the World Cup at the start of the competition and I have to say that I was impressed by Cristian Gamboa. He has been back in training now for a couple of weeks and he might be one that we see tomorrow night.

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Rosenborg are in the midst of their own crisis. The club have sacked the manager which has clearly irked the players who then released a statement calling for him to be reinstated. Sometimes when there is disharmony like that in the dressing room it can galvanise players.

We'll see tomorrow night what kind of fight they still have in them.

In any case, with Nicklas Bendtner the guy whom Rosenborg will look to do the damage, this is the kind of night where Ajer will really need to come into his own. You’d expect that the Norwegian kid will be tasked with putting the shackles on the striker at set-pieces.

I know there’s been a bit of chat about the fact that the Norwegians scrapped past Valur with a contentious last minute penalty but it would be foolish for anyone to underestimate them.

They have an experience guy up front in Nicklas Bendtner who has been there and done it. People talk about him as though he is way over the hill but he’s 30 – he will still have plenty about him.

The former Arsenal man is an exceptionally experienced Danish internationalist and he’ll play with his head in a game like this. One mistake and he’s savvy enough to punish it so I don’t think anyone should be under any illusions about this being a tough one.

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I don’t think Celtic could have got a harder draw than AEK Athens in the third qualifying round. It just underlines what an achievement it would be to make it to the group stages of the Champions League because they have had it tough in every round so far.

In saying that, I don’t think the players will be too concerned about what comes next. They’ll just be focused on tomorrow night and what they need to do to get past Rosenborg.

Ideally you want a clean sheet and a couple of goals to take to Trondheim. It doesn’t always work that way as we all know but that will be the intention. The absolute main thing is to try and keep a clean sheet because you’re always in with a chance if you have that.

I’d only just joined Celtic when I was on the bench for a game over in Trondheim. I’d actually scored a hat-trick the Saturday before against Dundee United but I still found myself on the bench as we headed over the Norway.

Read more: Former Celtic and Rosenborg striker Harald Brattbakk: "Champions League tie will still be alive in Norway"

I remember it was absolutely freezing. It was a miserable night – we lost 2-0 – but there will be better conditions in July than there were on October when we played.

I do think Celtic have looked particularly strong in the opening weeks of this campaign. There has been a genuine hunger and quality about them but these qualifiers are notoriously difficult.

It will be tense at Celtic Park tomorrow night but I think they will have enough about them to go out and get the result they need to take onto the plane next week.