ONE of the most fascinating duels in prospect in Thomond Park will be between the respective heirs to the thrones, Leinster's hotshot Ian Madigan and Munster's less flamboyant but very promising Ian Keatley.
It promises to be a classic showdown.
Madigan, the hitman riding high on a wave of emotion generated by a wonder performance in the Amlin Challenge Cup quarter-final victory over Wasps, is determined to show his worth in a rare chance to escape the shadow of his more illustrious team-mate.
Keatley has played plenty of rugby since joining Munster from Connacht. In his first season (2011-12) he actually played more games that Ronan O'Gara. But because of the enduring excellence of O'Gara, it is rare for him to start the higher-profile games.
The two out-halves are also in very different places mentally. Madigan, for example, knows that he is likely to be first choice for Leinster next season in light of Jonathan Sexton's imminent departure to France.
Keatley, like everyone else in Munster, is waiting to see what O'Gara's next move will be.
Whatever the make-up of Munster's squad next season, tonight's game is an opportunity Keatley must make the most of.
Realistically, the home side tonight have nothing tangible to play for.
As coach Rob Penney admitted in the aftermath of that tremendous win over Harlequins, the likelihood of them forcing their way into the top four of the Pro12 is very slim.
Munster's season is a success by virtue of their Heineken Cup exploits. They have more to lose tonight than they have to gain.
Their backline is already threadbare, with Doug Howlett and Keith Earls still on the injured list – the last thing they need is to pick up any more injuries.
It is safe to suggest that were it any other opposition in Limerick tonight, more than three of their front-liners – O'Gara, BJ Botha and Donnacha Ryan – would be rested for the game.
When it's Leinster, though, those bragging rights at stake are highly prized, hence the presence of so many of their heavyweights.
Tonight is also their last home game of the season and they will be loath to lose yet again to a side they haven't beaten in any competition since May 2011, especially in light of the feel-good factor engendered by their epic victory last weekend.
Leinster have plenty to play for, however.
Their position in the top-four play-off is secured but a home semi-final is not yet in their grasp. That is a powerful motivation for their endeavours.
Whatever Leinster's motivation, this game will, according to Munster's James Coughlan, be attritional.
"It's always a dogfight between us. They won't be thinking about the Amlin and we won't be thinking about the Heineken," said the back-row.
"These games are always occasions, regardless of league positions. I'm sure the match would be a sell-out regardless."
Leinster have placed so much importance on this game that they have also wheeled out their big guns. Brian O'Driscoll makes an immediate return to the side after suspension to partner long-term Ireland team-mate Gordon D'Arcy in the centre.
Cian Healy, Sean Cronin and Mike Ross make up an international front-row, while Sean O'Brien and Jamie Heaslip are included alongside Shane Jennings in the back-row.
It is a formidable Leinster side and they are narrow favourites for the game.
It's a big ask for Munster to front up to a side as good as Leinster after a five-day turnaround from their exploits in the Stoop and it is hard to see how they can overcome the after-effects of that performance.
The emotional drain on them has been enormous and the task facing them is, as Coughlan acknowledged, nothing short of monumental.
"They (Leinster) do everything well, they have quality throughout the team," said Coughlan.
"I don't think there is a non-international playing in the team at the moment.
"They can attack from anywhere, they can run all over you, they can kick you. We are going to have to be at our best to try and trip them up."
This contest promises to be an old-fashioned brawl between two sides who know each other intimately. And, as ever, there are sub-plots aplenty, with players hoping to impress on a number of fronts.
Lions coach Warren Gatland has confirmed he will be continuing to monitor Paul O'Connell's and O'Driscoll's form while he will surely also be awaiting dispatches on the likes of Heaslip, Ross, Simon Zebo, Rob Kearney and even, perhaps, Madigan.
There are also places on the Ireland tour to North America in the offing. Munster's Stephen Archer, Coughlan along with Leinster's Dave Kearney and replacement Kevin McLaughlin will be hoping to further their prospects of being included on that tour.
Encounters between Munster and Leinster are never boring and this won't be an exception.
For all their flair and skills, Leinster are also a big, physical side who will seek to dominate Munster.
For the first time this season, Munster showed last weekend that they can match up in the physical stakes.
In this regard, the battle of the back-rows will be hugely interesting.
Leinster have a clear heft advantage. Munster, though, base their physical game around a mentality.
It was that mentality that saw them dominate Harlequins despite giving up nearly a stone a man in the pack.
Leinster, though, are a far more formidable side than Harlequins and having something tangible to play for – a home semi-final spot – allied with the return of O'Driscoll should help counteract the 'O'Connell effect' Munster will be tapping into.
O'Connell will help provide Munster with a dominance out of touch. They also have more line-jumpers and a better defensive line-out.
Will these be enough to tilt the balance in their favour or will Leinster's supremacy in this fixture continue into next season?
Munster v Leinster,
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