Christopher Jullien is backing skipper Scott Brown to put the brakes on Rennes talisman Clement Grenier and drive Celtic towards a sparkling start in the Europe League.

The French defender returns to his homeland for the group-stage opener eager for the Scottish champions to make an early mark in the competition.

Jullien knows his team will face a stiff examination of the Roazhon Park.

Rennes emphatically dumped Arsenal on their own patch in last year’s knockout stages and have also overcome the star-studded Paris St Germain in Ligue One this term.

Littered with quality performers, Jullien picks Grenier is the main man.

Although star-striker M’Baye Niang is an injury doubt for the contest, Grenier is set to be in place looking to run the show.

Jullien accepts the former Lyon and Roma hero has the outstanding abilities to do just that, but he’s also confident that the close-up attention of Brown can rattle the playmaker out of his rhythm.

The Parkhead defender says that his captain can clamp the Rennes maestro as he explained: “The most important individual for them is Clement Grenier. He was famous when he was young.

“He is the midfielder who controls everything for them. He switches the play and has a great delivery from free-kicks.

“Behind him, the talented young players around him listen to everything he says. Grenier is a big part of their success.

“They [Grenier and Brown] are totally different and that’s why I’m happy going into this tie. I know Grenier and, if he has someone like Broony breathing down his neck, he won’t be the same.

“If your press him in an aggressive way, he’s not happy. If he doesn’t have the time and space to dictate the tempo and he has someone on him then he’s not so effective. “He’s still good, but he’s not the same and I’m sure our management will have noticed that.”

Jullien insists he and all of his colleagues will have to be on top form if they are to bring anything positive back from Brittany.

The hosts are just two points off leaders PSG the top of the Ligue One table and the Hoops stopper continued: “It’s not going to be as intense [atmosphere] as it was at Ibrox, but it will be a good.

“They had gone without European football there for seven years until last season, when they also won the French Cup.

“They had a really good crowd when they played Arsenal at home in the Europa League’s round of 16 in March and they beat them 3-1, although they lost 4-3 on aggregate.

“Rennes have made a really good start to the season and have even beaten Paris St Germain, which surprised a lot of people. They have a lot of very good young players, which is one of the things they are famous for.

“They have an excellent striker in Niang and some good midfield players. In fact, they are a good team. It would be a mistake for us to go there thinking otherwise. They aren’t a team you can take lightly and think everything will be okay.

“I’m sure everyone here will be focused on giving their best against them. If not, Rennes can be really dangerous. I know some of their players and I’ve played against them often.

“That strength of their team is the group and they showed it in the cup last year.

“The coach they have is really mentally strong with them. He tried to show them his way and it’s working.”

If Celtic can get a result, it’ll put to bed a poor record for the Frenchman at the ground.

Jullien has suffered defeats in the stadium, he’s been subjected to a red card and he’s not been able to savour the sweet taste of success.

Asked about his record in Rennes, he said: “At their ground, not so good. One draw and two defeats and I was shown a red card in one of those defeats.

“It was a really bad refereeing decision. I had switched off, it was the 94th minute and we were losing. Their player hit me when I was trying to clear the ball and I fell to the ground.

“I was on my side and I pushed him away with my leg. I certainly didn’t expect a straight red card. At home, I had one win and two draws against them, but it would be great to have a good moment in their stadium with Celtic. I feel as though I am due one.”

While Jullien’s main job tomorrow night will be to keep the ball out of the Celtic net, he has shown he is capable of posing danger at the other end of the pitch having opened his account for the club during the 4-1 win over AIK Stockholm in the Play-Off Round.

The centre-back knocked home after Brown looked like scoring and he smiled: “He’s okay with that. We were laughing about it and it was good for me to score. I told him that he could at least claim an assist!”