Lennon seems to have resolved these issues with aplomb. And while the Scottish champions were able to knock-off yet another comprehensive league win on Saturday thanks to the potency of their attackers – with double-scorer James Forrest and deadlock-breaker Odsonne Eduoard now having bagged 27 goals between them this season – it is the backline that is providing them the perfect platform to wreak their havoc.

It is easy to forget that in the early weeks of the season Kristoffer Ajer had to be pressed into action at right-back because of the limited options, while in that period doubts were being expressed as to the wisdom of lavishing £7m on close season signing Christopher Jullien.

Now the Ajer-Jullien axis in the heart of the Celtic defence is a partnership that has been central to Celtic having gone 377 minutes without the concession of a league goal, while Jeremie Frimpong as become a dainty diminutive dazzler of a right-back, whose chance has really only come because the other summer signing for that position Hatem Abd Elhamed has been rock solid in form but not fitness, his impressive showings, in turn, limiting the exposure given to decent-looking Stoke City loanee Mauritz Bauer – who will slot in against Rennes on Thursday because Frimpong’s meteoric rise to boy-of-the-moment was so unexpected the 18-year-old wasn’t even named in the club’s 25-strong squad for the Europa League.

The diminutive Jeremie Frimpong leads the celebrations at full-time. Picture: PA

Ajer, pictured inset, as with his manager who was moved to claim the Manchester City signing’s electric performance was among the best he had witnessed from a Celtic right-back – has been left agog by Frimpong’s foraging and finesse in all areas of his role.

“He’s a really fantastic talent,” said the 21-year-old. “Obviously, when you are young and you go into a dressing room, you have to work your way into it. But I think he has been incredible. Since the first training session, he has proven himself as a top, top talent. You can see with the way he is playing consistently that it’s not just a one-off. It’s there every single time and that’s incredible.”

The security Frimpong has been afforded by the Ajer and Jullien double act is a union that the Norwegian believes has blossomed because each brings different qualities to it, strengths that are central to giving Celtic the opportunity to clinch top spot in a European group for the first time in 16 attempts when they host their French opponents on Thursday with qualification from their section already assured.

It is no accident that Celtic have been able to establish a club record six-game run without a loss in European away games as the duo have gelled. Thursday’s encounter may be one of ten games in 32 days for the Scottish champions, but Ajer has no fears about coping with such a schedule.

“In the past couple of months, we have barely conceded any goals and that’s what we want to keep doing,” Ajer said. “He [Jullien] is one who likes to go up for every single challenge and I try to sweep up everything from behind that. It’s a really good partnership to have and we are learning more and more about each other.

“Thursday is a massive game. We want to win the group and we can do it if we take the three points against Rennes. It’s important for us on both counts in the fact that we have ambitions to go far in Europe and, if we win the group, we would meet a second-placed team, but we also want to just keep winning and everyone wants to play. You want to be part of it and keep the rhythm.

“That’s the most important part. The staff behind the squad works so hard every single day to keep us fit. You see it in every single game that we keep going until the end.”

Celtic star Krisoffer Ajer on why he works so well with Christopher Jullien