IT is football’s equivalent to the difficult second album. A previously unknown quantity arrives from foreign shores, makes a big impression on Scottish football, but now has to follow it up.

Christopher Jullien knows that his impressive form for Celtic since his move from Toulouse last summer will count for nothing if he doesn’t maintain those levels in the coming campaign, and the big Frenchman is also acutely aware that he is very much a known quantity this time around.

On the flip side of that though is the fact that Jullien now feels more comfortable within himself not only in the Scottish game, but as a leader within his dressing room. And he doesn’t intend on standing still either. His plan to combat any notion opponents have of figuring him out is to simply up his game even further.

“I think it is going to be tougher and more difficult for me now,” Jullien said. “The league now knows me and the opponents know me, but the biggest challenge is going to be doing it again for myself.

“When you enter into a new club and just arrive, you are a little shy sometimes to speak up and it takes time. But I know all of the players and the coaches and you can’t be lazy on things. You have to work harder and better to be more powerful and improve again.

“To have success and for the team to succeed and get to the top is tough. But to stay there is really difficult. Celtic does that every year, so I want to try and be the same.

“Last season was good for me. It could have better at times, but it was overall good and the task for me now is to make the next one even better.”

As much as Julien respects the opponents he will come up against on a weekly basis on the domestic scene, it is unlikely he will come up against any within the same stratosphere as the ones he is set to face in the coming fortnight as Celtic travel to France for friendlies against Nice, Lyon and Paris Saint Germain.

That will mean locking horns with former Celt Moussa Dembele as well as superstars like Kylian Mbappe, and Jullien is relishing the chance to test himself against the best as he feels it can only help him in the long run.

“It’s perfect to face such good players in the beginning,” he said. “You play football to face these teams and challenges.

“When I was in France, I played against those sides, although I had different team-mates and I’m now with a team who can win these games, even though they are friendly games.

“It’s good to be playing in France and against such tough opponents to see the levels we can match with them.

“The strikers that we will be facing are top-class. You want to come up against this and having battles against those guys is just perfect.

“I will be ready for it and can’t wait for the challenge. Whatever happens, I will be better for it afterwards.”

All the talk of friendly fixtures and possible opponents makes it seem as if something approaching normality is on the horizon at last for Jullien, although he is disappointed that the Celtic fans will be unable to back the team in the opening fixtures after being blown away by the fact that 50,000 of them have renewed season tickets.

He is accustomed to the challenge of playing in front of empty stands though after getting a taste of it in Toulouse, and says that the thought of paying those Celtic supporters back with wins is the only motivation he needs.

“When I saw the sales of the season-tickets, I thought this is crazy,” he said. “This is huge. And we are going to give everything to pay them back.

“Playing without fans is going to take concentration, but the team has shown me we are going to have the strength to do that.

“We are focused on the field and concentrate on our jobs and I know the situation because I have already faced it in France one time.

“I was playing a two-legged game for not to go down with Toulouse. We played the first game behind closed doors in a stadium which was not the stadium of the other team because their fans did big damage at other another game. So, they put the game at another stadium.

“The motivation at the beginning of the game in the first five or 10 minutes was the most difficult, but, when you get that, everything is normal.

“When you are focused, you play your game and it is going to be good. We are going to get through and just wait for the days until we get the supporters back

“I can’t wait for the first game to kick off and try to make a new achievement."