EUROPEAN football after Christmas is assured for Celtic once again this season regardless of the outcome of their encounter with Bayer Leverkusen in their penultimate Europa League group game here in North Rhine-Westphalia this evening.

The Glasgow club will finish, at the very worst, third in their section and drop into the knockout rounds of the new Conference League following their match against Real Betis at home next month thanks to their back-to-back wins over Ferencvaros.

Yet, manager Ange Postecoglou understands that he and his men must always strive to be the very best they can and is acutely aware they will not survive at Parkhead if they are content to accept anything less.

He will instruct Callum McGregor and his team mates to go all out for victory in their Group G match against their Bundesliga rivals in the BayArena tonight, record their first ever victory on German soil and keep their hopes of reaching the last 16 alive. 

“You’ve got no choice,” he said. “Unfortunately or fortunately, whatever way you want to put it, when you join this football club, that’s what you are signing up for.

“You are not just signing up to play for a club that has great standing and has great support, you are signing up to be just that, to be hungry for success. Because if you are not, you won’t last here. Not if you are a player, or a manager, or a member of staff here. 

“That’s the expectation. You have got to walk around here whether you have been here for a couple of months or for 10 years and approach every game as if we haven’t had success for a long time because that’s the demands and that’s how you stay on top of your game always.”

Postecoglou added: “If we fall short, at least we’ll know we’ve given it all and we’ll know where we need to improve.

“But if you go out there sort of trying to just have self-preservation or playing safe or not going out with the intention of leaving everything out there, you’ll never really know.

“That’s what we’ll do in every game, take on the challenge and, hopefully, we can be successful and move on from there.”

It is a big ask to beat Leverkusen; their opponents ran out comfortable 4-0 winners in their last meeting in Glasgow back in September, are undefeated in their section and can ensure their progress with a draw.

But Postecoglou, who will be able to start Stephen Welsh after the centre half recovered from the knock he suffered in the Premier Sports Cup semi-final win over St Johnstone at Hampden on Saturday, is convinced his charges can give a far better account of themselves this time out for a number of reasons.

“It’s a massive challenge,” he said. “We are playing one of the top teams in Europe. To all intents and purposes they are a Champions League side and we are playing them in their backyard, so the goal can’t be underestimated. But we have to go there and see how we measure up against that.

“But we are obviously more settled. Before the last game, Kyogo (Furuhashi) had been out for a month and that was his first game back. Callum had been out for three weeks and it was his first game back. So we were going through a very unsettled period. We are definitely more settled.

“The fabric, the core of the side and the way we want to play, won’t be that different. There’s no doubt results help with belief and our confidence, but I’ve tried to make sure the attitude doesn’t change.

“Even when we were going through a rocky spell, the way we train, the way we conduct and present ourselves, you can’t just be dependent on results. We have got to believe in ourselves, go out and take a game to opponents, work hard every day in training.

“That’s the key to being successful. If you just wait for things to go well for you and don’t come out of your shell, you are going to miss opportunities. We’re settled, the team has belief, but in terms of approach and our daily interaction with each other, it’s still the same. It’s the focus being on the best team we can be.”

Postecoglou continued: “It’ll be a challenging game for us. They are a good side. They have picked up their form in the league as you can see.

“We have obviously played against them once and we know they are a side that is very quick on transition with quality players throughout their team. We are going to have to put our best foot forward to match them. It’s a challenge for us to go there and try to impose our game on them.”

Celtic impressed going forward in their Europa League matches against Real Betis in Spain in September and Ferencvaros in Hungary earlier this month and scored no fewer than six goals.

However, Postecoglou knows that Joe Hart, Anthony Ralston, Stephen Welsh Cameron Carter-Vickers and Josip Juranovic will need to be switched on to prevent Leverkusen, who were ruthless on the counter in September, from inflicting another painful defeat on them.

“We have to make sure that we are concentrating all of the time and well disciplined in our approach,” he said.

“They are a team that will wait on any mistakes we make and punish us. When the first game was at 0-0 in the first 20-odd minutes, we probably created the better chances. But then we made a mistake and they scored and we lost our composure and concentration for a little bit.

“It’s always a tough battle away from home in Europe and especially this one. It’s important we have our concentration levels and discipline when we have the ball and, if we make mistakes, we don’t let the opposition punish us for it.”