Irish playmaker Jonathan Sexton can see barrel-chested French centre Mathieu Bastareaud looming down on him when they face off in the World Cup.

“He’s a hard man to stop and I know it better than most!” Sexton only half joked.

Either man could decide the crunch Pool D match in Cardiff on Sunday to see who avoids a likely quarter-final against defending champions New Zealand.

Thirty-year-old fly-half Sexton is key to Ireland’s hopes of beating the French.

Bastareaud terrorises opposing defences and he did the same to Sexton, having caused one of his four concussions last year. The Irishman had to be stood down for 12 weeks due to the concussion protocols.

On Sexton’s return to action in the Six Nations against France this year, Bastareaud’s elbow connected unintentionally with Sexton’s head leading him to visit the blood-bin.

“I asked Bastareaud after the game why always me and he just laughed,” said Sexton at the time.

However, with the showdown of the Six Nations heavyhitters on the horizon Sexton accepts he will have to put up with being the centre of Bastareaud’s attentions again.

“I’ve come off second-best a couple of times but he sucks in a lot of defenders and he looks like he’s got himself in really good shape.

“So we’ve got to be on top of our game from that point of view, and I’m sure we’ll come up with some kind of plan to help us stop him,” he added.

Sexton, who has been in terrific form in the two pool games he has appeared in, scoring 25 points including a try, said he did not imagine the French would alter their tactics from the previous time.

“They said before the last game they were going to come down my channel because I was obviously coming back from a lay-off, and I don’t see it being any different this time,” said Sexton.

Ireland coach Joe Schmidt has said he is fearful every time Sexton goes on to the pitch because he, like other fly-half greats such as Jonny Wilkinson, does not shirk a tackle.

However, Sexton said he did it more because it is what is expected of him than taking any great thrill out of putting in a heavy hit on an opponent.

“I don’t know if I like the physicality, but it’s part and parcel of the modern game,” he said.

“Everyone on the pitch has got to be able to contribute defensively and physically, and it’s not often you see guys that can’t do it anymore. And hopefully I’ll tick that box.”