WHEN the referee blew the final whistle at the end of Celtic’s win over Lazio at Parkhead last month, Christopher Jullien made his way over to Kristoffer Ajer and Fraser Forster almost as quickly as his jubilant team mates had rushed across to congratulate him on his late goal.

The French centre half was, no doubt about it, the hero of a remarkable fightback against and famous 2-1 triumph over the Italian visitors after getting on the end of a Ryan Christie corner and powering a downward header into the bottom left corner with little over a minute of regulation time remaining.

Yet, the match winner could still recall the errors which he had made against Simone Inzaghi’s side at the back and was, amid wild celebrations on the park and in the stands, eager to thank the individuals who had been responsible for ensuring they hadn’t resulted in Neil Lennon’s team conceding again and possibly squandering their chance of salvaging a result.

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“After the game against Lazio there was a lot said about the goal because it was one of the last things in people’s minds,” said Jullien. “But the two guys I went to see first at full-time were Kris and Fraser.

“I was not happy about my second-half at all. I miss movements of my striker. Kris did great to come back and the striker hit the post. If he hadn’t come back then they could have scored and the game could have been completely different. There was also a moment when I slipped and then Fraser saved us. It could have been a totally different game.”

Jullien has more than justified the £7 million fee that Celtic parted with to secure his services from Toulouse during the summer and not just because of his goal against Lazio; the 26-year-old has established himself as a first team regular, forged a solid central defensive partnership with Ajer and repeatedly proved himself both domestically and on the continent.

His reaction to a Europa League result that put his side on top of their section after three games and in a strong position to secure a place in the knockout rounds, though, shows that he is unlikely to become complacent about his promising start to his time in Scotland. Jullien is clearly determined to improve further. There is never any let-up in his pursuit of perfection.

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“When we finish the game, sometimes the staff and the trainer will say ‘don’t worry, everything’s fine’,” he said. “But in my mind I always remember the mistakes and think about how things can be better the next time.

“I’m working every day to be better—to be more efficient with my long balls and my headers. In the last European game I scored, but I should really have had two or three goals. Every day I am working on that and we have good staff behind us to help. I can’t wait to get better for the team and the club.”

Jullien understands there will be no margin for error at he back when Celtic square up to a Lazio side who need to prevail to keep alive their hopes of reaching the last 32 in the Stadio Olimpico in Rome on Thursday evening.

“They are behind us so they have to do something,” he said. “They have to attack and score and win. It’s definitely going to be a different game. It’s going to be difficult. But I can’t wait to be out there. We’re going to look for the win ourselves.”

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Ciro Immobile, the Italy striker who started the last match on the bench, is likely to be involved from kick-off and Jullien knows that he and his fellow defenders are in for another torrid evening against a man who is, with 12 goals in 10 appearances, the top scorer in Serie A in the 2019/20 campaign.

“He’s simply an international player, a big striker known for scoring a lot of goals,” he said. “He knows what he’s doing. He does his job perfectly. When he came on the field he didn’t have so much time, but I’m sure he’ll be there this game and ready for the big fight. We have to be ready because he’s a really good player.”

There are fears the Group E match in Rome could, as was the case in Lazio’s last home fixture against Rennes last month was, be marred by the racist behaviour of the ultra element of the home support even though the Curva Nord, the section of the stadium which houses them, will be closed as the result of UEFA disciplinary action.

If Jullien is targeted, though, it will simply backfire on his abusers. He flourishes in big games when the opposition team has the majority of the crowd on their side and relishes nothing more than getting results against all the odds.

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Asked if he finds playing in an intimidating atmosphere demanding to deal with, he said: “Oh no, I love that! I don’t know if it makes me a better player but more focused, for sure. When you play away in a hostile environment and you can make the crowd silent, it’s really enjoyable.

“When I played in France there were games in Marseille with a lot of good fans. We got a draw and all the fans flipped to the other side and were more cheering us. It was a difficult thing. I had some games like that. But it’s not the same as here. Here it’s another level and it’s really enjoyable.

“Playing Rangers at Ibrox this season was really a good game and we performed well. The fact the stadium went silent is really enjoyable. We had some fans behind our back, but I have to admit I was more focused on my opponent in that game.

“It was the first Old Firm match that I played and I tried to not get the crowd thing stuck in my mind. I just remember enjoying the feeling of victory at the end and enjoying it with the fans.

“I think we’re going to go there and they’ll do everything they can to beat us. I just can’t wait. We will see how everything develops on the field.

“It’s our goal to stay on top in the group and that means we’re the target for the other teams. I’m sure we’re going to perform well because we keep having trust in ourselves. It’s them who have to attack us and try to beat us. We’re going to do our job.

“I prefer to focus on the field. I know the stadium isn’t going to be for us, if the fans can go and behind our back it would be lovely. But we will just try to come back with the victory and do our job. I’m not scared about that. I’m focused on the field but I really hope the two sets of fans can make a great atmosphere.”