Leinster coach Joe Schmidt has called on his players to "respond to" the intensity required to match "the big, angry, red men" of Munster in the Magners League at Thomond Park on Saturday evening.
In order to achieve Leinster's sixth straight win over League leaders Munster, they will have to find a way through or around Paul O'Connell.
Schmidt knows this won't be done easily.
In his previous incarnation as assistant coach at Clermont-Auvergne, Schmidt had to sit and watch as Canadian Jamie Cudmore was red-carded in a punch-up with O'Connell in a Heineken Cup match that was there for the taking.
"The last time we (Clermont) went we ran them pretty close," he recalled.
"I was a bit disappointed on the day. Paul O'Connell got five good ones in and Jamie Cudmore got five good ones in.
"But, Jamie didn't know when to stop. He was a bit of a glutton for punishment, so went for a few more. He got the red. We battled a bit that day.
"They scored with four minutes to go. We led 13-11 with 14 players. It does prove that you can stay in the game against them. But, staying in the game is not enough, you've actually got to keep them out and get yourself over the line.
"I think they have an astute coaching staff and I know they have quality players. Paul O'Connell back for them is a massive boon. He really lifts the whole level of expectation and confidence for them within that group".
It is not just an O'Connell problem they will have to solve on Saturday. It is a Munster problem. Their dismal recent record against their greatest rivals only fuels the fire within.
"It is certainly a pressure cooker atmosphere. I think it is something our players are pretty keen to respond to. I know they won there last year, albeit by a point," Schmidt said.
It was Leinster's first win in Limerick since 1995, delivered by Jonathan Sexton's 66th-minute penalty. Now, they are very much in the mood to make it their second in 12 months.
While Sexton applied the vital swing of his right boot, full-back Rob Kearney, currently injured, executed the only try of the game, converted by Sexton, for the vital ingredient just before the break.
"It was one of those tries that did not come out of the set-piece guide book. It was a lucky bounce for us, bad bounce for them," admitted Schmidt.
"In fixtures like this, it is only one or two points. There's not much between the two teams. It does come down to a bit of luck and a little bit of timing and effort on the day."
There is an argument for holding back based on what lies ahead for Leinster -- there are just 400 tickets left for their Heineken Cup quarter-final against Leicester Tigers on Saturday week.
However, this is a sport where there is no room for the half-hearted. It is blood and thunder or a quick surrender in what is sure to be an electric atmosphere.
"I don't think there is going to be any hesitation of the physical side of things. It is great preparation as long as you don't get too many guys knocked around," said Schmidt.
"Across the park, defensively they are very difficult to break down. They are very, very good at slowing ruck ball down. It is very hard to play a high tempo game against them.
"They know that is probably what we'd like to do. They will stick to their strengths and try to blunt ours. It is not often they'll be matched physically, especially at home.
"You've got to go there with, I suppose, the desire to do. And there has got to be a fair bit of it because they are big, angry, red men."
What a battle it will be.