THEY brought in a foreign manager in the summer who has attempted to get a group of talented young players to embrace a new style of attacking football.

When his tactics have worked, his side have blown teams away both at home and abroad and delighted their supporters. When they haven’t? They have slumped to heavy and humiliating defeats which have angered their fans.

The experiences of Gerardo Seone at Bayer Leverkusen this season have not been entirely dissimilar to those of Ange Postecoglou at Celtic. The Swiss coach is, like his Greek-Australian counterpart, in the process of implementing a game plan that is completely different to that of his predecessor. Displays and results have fluctuated.

Going forward, the German outfit have been mesmerising to watch at times. But defensively they have failed to convince on occasion and have conceded soft goals. Sound familiar to any Scottish team?

They certainly showed their best side against Celtic – who they will play once again in their penultimate Europa League group game at the BayArena on Thursday evening – at Parkhead back in September.

Goals from Piero Hincapie and Florian Wirtz in the first-half and Lucas Alario and Amine Adli in the second gave them an emphatic 4-0 triumph. They will be looking to scale those heights again and secure a victory that will book their place in the last 16 of the competition with a game to spare. But with this Leverkusen side there is no guarantee what will happen.

Since their Celtic triumph, they have been beaten at home by Borussia Dortmund, Bayern Munich and Wolfsburg and held to draws by Cologne and Hertha Berlin away in the Bundesliga. They were also knocked out of the German Cup by second tier Karlsruhe. Much depends on which Leverkusen team turns up this week.

“Leverkusen have been very up and down,” said Alexander Haubrichs of the Express newspaper in Germany. “I was at their game against Cologne last month and it summed up their season.

“They had a fantastic first-half, took a 2-0 lead and should have been 5-0 or 6-0 up. But they drew 2-2 at the end of it. That has been typical of their performances all season. They have enormous potential and great talent, but it is a young squad.

“The team has not yet fully adapted Seone’s game plan. He has a lot of ideas on how his side should play and he needs more time before the changes come to fruition. To be honest, I do not see a great deal of an improvement from last season.

“They needed to beat Bochum (Leverkusen won 1-0 at home on Saturday thanks to an early Adli goal). They had only won two points from their previous four Bundesliga games so Seone was under pressure. They are expected to qualify for the Champions League and they were outside the top four before the weekend. It is not where there they want to be.”

Jeremie Frimpong, the Dutch full-back who signed for Leverkusen from Celtic in an €13.5m transfer back in January, has featured regularly under Seone despite being bought by Peter Bosz. However, he is like many of his team mates; gifted but lacking in maturity and prone to lapses in concentration.

“For a long time, right back was a problem position for Leverkusen,” said Haubrichs. “Frimpong has come in and been a regular starter under Seone. The manager likes his full-backs to get forward and attack.

“Frimpong has been good going forward, but he has also made mistakes at the back. Against Cologne, he was one of the players who was responsible for the team surrendering their lead and drawing the game.

“Alongside him, Jonathan Tah, who made his comeback in the national team against Armenia on Sunday and helped Germany to win 4-1 away, is a very experienced centre half. But, like Leverkusen as a team, he has his ups and downs.”

Leverkusen showed they can cope without the injured Patrik Schick, the Czech Republic striker who scored twice for his country in their opening Euro 2020 group game against Scotland at Hampden back in June, in Glasgow in September.

The 25-year-old, who has been sidelined with a ligament problem for a month, only came off the bench with 16 minutes remaining when the visitors were leading 3-0 and the three points were assured.

“Schick is a very good goalscorer and he normally starts,” said Haubrichs. “But Leverkusen have so many good young players that sometimes, like in Glasgow, he is left out of the starting line-up. That shows the strength in depth they have.”

Celtic will not, as Leverkusen were when they came to Parkhead, be met by a wall of sound when they take to the field in the BayArena on Thursday evening. Still, it promises to be, despite their rivals’ issues, a difficult outing for Callum McGregor and his team mates.

“It is not a stadium like the RheinEnergieStadion or the Westfalenstadion where there are a lot of fans who create intimidating atmosphere for an away team,” said Haubrichs.

“There will not be so many Leverkusen fans at the Celtic game. There were only 11,000 at the Fenerbahce game and 15,000 at the Real Betis game.  But Leverkusen certainly prefer to play at home. As I say, they like to play offensive football and they are better at that at home.”