For 45 minutes inside the impressive Aviva stadium in Dublin on Saturday evening there was a reminder of just what Celtic have been missing in recent seasons.

Doing it for real is the prime aim for this season.

Astana are due in town this week as Celtic look to consolidate their passage deeper through the qualifying campaign, with that away goal from the first leg in Kazakhstan giving Brendan Rodgers’ side a slight edge in the tie.

The Celtic manager still believes his side are a work in progress – he wants to get in an additional four bodies to add to Moussa Dembele and Kolo Toure, with Scott Sinclair and Manchester United's Paddy McNair on the radar - but the immediate attention now is on the Champions League.

READ MORE: Nir Bitton fighting for fitness ahead of FC Astana clashGlasgow Times: Brendan Rodgers wants four new players before the window closes

There were lessons to be learned from Barcelona at the weekend, inevitably, but by and large the game served to underline much of what Rodgers already knows.

“Bless him,” he said in reference to the much maligned Efe Ambrose after the Nigerian defender scored a peach of an own-goal – “any striker would have been proud of that one” and was nut-megged by Luis Suarez in the build-up to Barcelona’s third.#

READ MORE: Nir Bitton fighting for fitness ahead of FC Astana clash

Of the many times that Celtic fans have raised their eyes to heaven with regard to Ambrose, it is fair to say they have not been wishing him graces from above; an appeal for divine intervention would be more like it.

Ambrose was a forlorn figure by the time the interval sounded but in fairness to the player he had actually fared not too badly until his implosion. And that in itself is the problem for Celtic – Ambrose has been much maligned, some of it unfairly, but he simply cannot be trusted in pressure situations.

There was a small chorus of jeers directed towards the Nigerian defender, something Rodgers wasn’t too enamoured with. In all likelihood Ambrose will not feature much once the Celtic defence has been settled, but Rodgers was quick to stand by his player.

“If it was that – I didn’t hear that myself – it’s not nice. It is a man who, whatever his faults are, he is a real good guy who gives his all for the club, devotes his life to Celtic. He prepares well, he trains well, he doesn’t cheat. He trains every day and he is a man who wants to get better. It is difficult, if that did happen. The Celtic supporters will support anyone who plays, whether that is Efe or anyone else who pulls on the green and white jersey – everyone needs that support.”Glasgow Times:

Given that Celtic closed the game out against Barcelona with four kids in the backline, there is a clear need for reinforcements.

Rodgers has been forced into playing Eoghan O’Connell because of the defensive issues with injury problems and he was effusive in his praise for the young Irishman.

“O’Connell was excellent for 45 minutes,” he said. “He coped very well. He knows the game. He is calm in possession, he doesn’t just get rid of it.”

One Celtic player who has picked up where he left off last season is Leigh Griffiths. The striker netted an opportunistic striker against Barcelona in Dublin but he still has a sharpness about him which bodes well for the campaign which lies in wait.

“Leigh is a terrific striker, there is no doubt about that. I know that even from the short time I’ve worked with him, he has a natural instinct,” enthused Rodgers. At whatever level he plays he’ll get goals. It’s been nice for him to get them in the qualifiers.

“So he’s really starting to find his feet. He’ll be important for us this week as will the supporters who will be critical.”

The outcome of Wednesday’s game against Astana will effectively set the tone for Celtic’s season; seeing the game out will lead to a play-off for the Champions League or, at the very least, a place in the Europa League.

However, a 1-1 draw, while tilted in Celtic’s favour because of the away goal, is notoriously difficult to see out, with just one goal possible changing the complexion of the tie entirely.

“We are really going to need them [our supporters] in the next game to help us get over the line,” said the Celtic manager. “We have a job to do and need to go and put a performance in.

“Astana are good on the counter attack with fast players so there will be moments in the game where we need to cope with that. But the first-leg was a really good result for us. Coming away with a draw was good as it’s a very unique situation preparing the team right now, You can’t train enough with the fitness coming from games.

“But the Champions League is where we all want to be, it’s what we strive for. It’s the elite of European football; and Scottish football is better served having a team in there.”