Blues hit by big tank setback
It is the news no Leinster nor Ireland supporter wanted to hear.
Seán O'Brien will be out for the guts of six months due to a shoulder reconstruction which will take place in Manchester today.
"The infection that he got post-surgery last time meant that the graft wasn't as successful as everyone would have liked and he's having to have that redone," said coach Matt O'Connor.
"The graft didn't take and as a result he needs that tightened up.
"Because of the softening of the tissue with the infection, the screws that were put in weren't as successful as we would have liked."
Cian Healy is out for 4-6 months. This moves the weight of responsibility on to the shoulders of Jack McGrath, Dominic Ryan and Rhys Ruddock as Leinster look to the next generation to stand up to Munster.
One man's bad break is another's open door. Ryan has spent the greater part of the last two seasons dealing with injury and disappointment.
This is his time to shine before Shane Jennings sticks his head around the corner after overcoming a hamstring problem.
"It's great to see Dominic get more and more rugby because he had a pretty chequered couple of seasons injury-wise and selection-wise so from that end for him to get a run of games, it's brilliant."
O'Connor was keen to push how the animosity that has kept the Leinster-Munster fire burning is still there.
"I think there'll be a fair bit of hate come 6.30 Saturday," he said. "It's easy to be composed about it now. But, the reality is that there's a lot at stake. There's four points. There's bragging rights. There's Ireland selection.
"There's all sort of balls in the air when it comes to this fixture. That's what makes it special.
"From that end, we'd like to go into it without any red mist. The reality is there will be a lot of sharp shoulders on Saturday night."
The simple fact that Leinster's O'Brien, Healy and Jordi Murphy, Munster's Donnacha Ryan and Keith Earls, and Ulster's Dan Tuohy have been ruled out for November means automatic provincial promotion for some, maybe even national headlines for others. Heck, the uncertainty over Leinster wings Dave Kearney and Luke Fitzgerald creates expectation for Fergus McFadden and Munster's Simon Zebo.
O'Connor is a fan of the mercurial Mr Zebo. "If he was in our group, we would be trying to give him the ball as often as we can because he has that ability to create from nothing.
"There's fewer and fewer of them in the game these days.
"From that end, I think he's an unbelievable talent who should be given the scope to grow and develop."
Lock Kane Douglas is another expected to move his game on to a new plain now that he has his feet firmly under the table at his new club.
"It was a hell of a lot of detail for him to absorb in five days, which he did incredibly well at. The extra training week should prepare him to be that bit better again.
"It is a huge opportunity to get him some more rugby and I think he'll get better and better every time he plays."
Leinster and Munster have each started with two wins and two losses.
Can O'Connor compare and contrast? "I think, a little bit like ourselves, they've had a little bit of disruption through availability of senior blokes at the start of the season which makes it hard.
"Munster will come with a pretty simple approach on Saturday to play in the right areas, to be very confrontational and to try and break us down and force errors out of us.
"The challenge for us is to make sure we are accurate in the things that we want to do, we deliver on the bits that make us good and from that end, hopefully get the result."
Leinster have shown a serrated edge to their attacking game, at times, at The RDS. They want to bring that across the road to The Aviva.
"There's been pleasing elements across the board, probably punctuated by two defeats at tough places to win," said O'Connor about down days at Glasgow and Connacht. "We'll be looking at an 80 minute performance where we've sort of stopped and started, done some very, very good things and let ourselves down in other areas.
"You won't get away with that against Munster, regardless of how they're going. It's a massive game for both groups to see where we're at.
"It's a home game for us in front of a full house, and we will hopefully put out a performance that we can be proud of.
"If we can achieve all of those things then I think the result will be secondary and we'll be okay."