A loitering ambulance hinted at something amiss at Lennoxtown yesterday afternoon.

As Brendan Rodgers revealed, however, that the provision of emergency aid was little more than another Uefa requirement 24 hours before a Champions League game, putting any consternation firmly off the radar.

For Celtic, though, this is the game where they will look to inflict the damage on an Astana team who boast something of their own fortress away from home. Tonight’s 90 minutes is all about ensuring that there are no wailing sirens at this stage of Celtic’s season as the Parkhead side look to consolidate a place in the group stages of the Champions League for the second successive year.

If Rodgers felt nervous ahead of a game that defines Celtic’s campaign, he did a good job of disguising his anxiety.

He might well have spent last night tossing and turning as he absorbs the magnitude of this game, but he was calm in the face of all pressure yesterday afternoon.

“If you think too much you could have the sleepless nights,” he said. “My way is always the same. We know the consequence of it. This year has been much smoother for us and that’s down to the maturity of the group and how they understand what we look for and how they play and the approach.

“You can’t get too emotional. They’re emotive games, of course, and we want passion and aggression but in order for us to get to the other side you have to stay calm.

“So, the players have learn that. We played enough big games last season and from what we’ve seen over this campaign so far, with that bit of maturity in knowing our ideas of the game, if we stick to them we’ll get our rewards.”

Nir Bitton will partner Jozo Simunovic at the centre of defence this evening, a tactic that will be lauded should Celtic get through the tie but one that will be used as a major criticism if the club stumble.

Bitton’s emergency cover at the back comes after Dedryck Boyata and Erik Sviatchenko both suffered injuries but the lack of defensive cover will be one of the sticks to beat Celtic with should they not vault this final hurdle.

Former Celtic striker Chris Sutton publicly stated this week that Bitton at the back was a gamble, but Rodgers insisted that it was not a decision he has come to lightly.

“If it was a big gamble I wouldn’t do it,” said the Celtic manager. “I have taken risks all my life and 8/9 times out of 10 they pay off. For me, it is not a risk. You are also looking at the game.

“If I am playing against a team who are totally bombarding you with high balls and direct balls and you are away from home, then maybe you think differently. But you also have to think of the level of the game.”

There was a suggestion that Anthony Ralston could play on the right-side of a back four with Mikael Lustig stepping into the centre-half position, but Rodgers hinted that the tension associated with the game and what is at stake may well be too much for the teenager.

“You want to put young players in but you don’t want to hurt them either because there are pressure games and normally little bits of experience can get you though,” he explained.

“Ok, it might not be perfect playing Nir there but he has got a good idea of what he is doing, he has got the right profile, he will go and attack it, he will head it and he can play football. I don’t see it as a risk. I will make risks but they will always be calculated.

“I would never just sit down and say let’s play him in there because he is tall. There is a certain dynamic to it and he has done it very well.”

Bitton has been in the spotlight after he got away with a clumsy challenge on Miles Storey on Friday night at Firhill, a challenge that could well have conceded a penalty.

“You miss the number of times he does go and be aggressive,” said Rodgers in the Israeli’s defence. “He is up against a striker that uses his body well and it is just a decision at the end of the game. He was maybe half expecting Craig [Gordon] to get it, he doesn’t and he takes it away.

“It could have been a penalty but in lots of occasions those moments will go from him. You could have a defender in there who doesn’t get back quick enough so there are pluses and minuses.

“There will always be a risk if you are putting in a midfield player who doesn’t normally play there. You have to think about it and weigh it up and for me if he needs to play there, he can play there.”