Ireland not taking Boks' replacement hooker Deon Fourie lightly

South Africa suffered a huge blow to their squad last week when hooker Marx was ruled out for the remainder of the Rugby World Cup after suffering a knee injury.

The injury took place during training and the aftermath saw debate over whether the Boks would bring in a like-for-like replacement or look elsewhere for cover.

The latter proved to be the case as flyhalf Handre Pollard was added, meaning that Fourie and Marco van Staden would help ease the load on Bongi Mbonambi.

O'Connell knows Fourie from his time coaching in France and had nothing but praise for the versatile veteran, who is on the bench against Ireland this week.

"I don't know about that," he replied when asked whether the Springboks losing Marx makes their lineout more contestable and an area they will look to target.

"Deon Fourie has always looked very competent to me. I remember when I was down here in France watching him swapping from the back-row into hooker for Lyon and he was absolutely incredible.

Follow all the Rugby World Cup fixtures in our live score centre

"With a coaching staff who have been together a long time, they know their lineouts. There isn't a whole lot of change. They have a lot of continuity in that regard, they have very good options in the air. I would say they feel pretty confident about it.

"Deon Fourie is a wise campaigner, he's been around, he's really experienced. We will be trying to pressure them for sure, but in the same way we would try to pressure any hooker that comes off the bench."

The Ireland v South Africa clash in Paris has been dubbed the game of the week and O'Connell admits they must play to their own strengths in such a big match.

"It's right up there," he said on the scale of the fixture. "Obviously we have known our pool opponents for quite some time, so there's been plenty of chat about it and days where we've had a particular focus on teams within the pool, to figure out what they're about and what we need to be on that day. The fact we've known for a little longer means you have more time, but it's not been massively different.

"One thing you can't do on these occasions is move away from how you prepare and what you stand for. You have to tweak things a little bit so you are ready for the opposition, for sure, but one of our big strengths is understanding what we're about and how we go about delivering that. It's hard enough every week ensuring we deliver what we stand for. We do focus on the opposition but not as much as you might think."

Selected matches will also be available on SABC Sport.com's live streaming channel

It promises to be an epic occasion at the Stade de France as two of the tournament favourites meet, with O'Connell relishing the scale of the task ahead of them.

"It's going to take a big performance for sure," he said. "They are an excellent side, they have been together a long time as a group and a coaching group, they understand how they want to play and deal with certain situations in a game. They have developed their game since the last World Cup and a lot since last November in particular. Our boys are under no doubt about how big a challenge it is.

"They obviously present a big physical challenge - I think we present a big physical challenge as well - but also a really technical challenge. They are a very smart side. That is probably one of the things you admire the most - the smarts they can bring along with their physicality."

He added: "It's a strength of our side as well. We speak about this Irish team and what they stand for. They have got to bring everything they have brought to big occasions over the last few years - a Test series decider down in in New Zealand in Wellington, a Grand Slam decider, a tough autumn series against some very tricky opposition.

"We have always found a way and figured it out and it is a real strength of theirs. They are going to have play super well tomorrow but also figure things out, which is something I really enjoy watching them do when they have a challenge in front of them."

READ MORE: Springboks promise to leave nothing on the field against top-ranked Ireland