THEY’D BOTH swap a defeat today for a win next week. The Heineken Cup is the bigger competition and next weekend’s quarter-finals offer no second chances. But this won’t count for a jot come kick-off.

Pitch these two on a beach in front of two men and a dog – not implausible earlier this week – and we should have another, and quite timely, celebration of Irish rugby.

Throw in a capacity 27,000 crowd, a 7.30pm kick-off, a top of the table Pro12 eight-pointer between the European and League champions, and all that still probably comes second to the primary mater of pride between local rivals.

Hence, in the last six years, it’s hard to recall one meeting that wasn’t utterly absorbing from first to last, with last May’s Grand Final here one of the stand-out fixtures of the season; it’s only blemish being that it came a week after Leinster’s heroic comeback in the Heineken Cup final.

Seven days later, the newly crowned European champions threw the kitchen sink and the dining room table at Munster, only for the home side to defend their line heroically before finishing with a scrummaging flourish against wilting opponents.

Bonus meetings such as that and the two Euro semi-finals in 2006 and ’09 apart, as an aside, provided there are no injuries, the league fixtures are usually judiciously placed either before the Euro campaigns kick-off or return to the knock-out stages.

All the more so with the haemorrhaging of Welsh players to the Top 14, this match-up is by some distance the nearest equivalent to a European tie.

When they finished the pool stages, the provinces had had their players together for 14 unbroken weeks and had reached optimum levels of performances, as was spectacularly evidenced by Munster’s 51-34 win away to Northampton.

Leinster went through that entire segment unbeaten, and although they just about extended their unbeaten run to 20 games, last week lost with Brian O’Driscoll and Leo Cullen re-introduced to the team, and Brad Thorn introduced, that record went.

This fixture also serves another purpose in that it swiftly reminds the international set – though centrally contracted in the main – as to where they hail from, not only returning to their provincial teammates and representing both their provincial jerseys and supporters, but against many of their teammates from the previous nine weeks.

Comparatively harder hit by the Six Nations, Leinster welcome back Rob Kearney, Gordon D’Arcy (making his 200th appearance for the province), Jonathan Sexton, Eoin Reddan, Sean Cronin, Mike Ross and Jamie Heaslip (who captains the side), as well as recalling Devin Toner, Kevin McLaughlin and Shane Jennings as Joe Schmidt looks to give game time to those most in need of it.

The net effect is that Richardt Strauss, Leo Cullen, Isaac Boss and Fergus McFadden drop to the bench, where they are joined by Cian Healy and Sean O’Brien. That said, it’s a helluva bench. D’Arcy emulates Shane Horgan in becoming the second Leinster player to reach 200 caps for the province while even more remarkably, this game marks Luke Fitzgerald’s century.

Munster have made five changes in personnel, welcoming back Keith Earls, Donncha O’Callaghan, Peter O’Mahony and Ronan O’Gara, who captains the side, from their Six Nations’ exertions, with Earls’ return seeing Johne Murphy revert to right wing to the exclusion of Denis Hurley.

The other change sees Marcus Horan, looking rejuvenated and healthy again, preferred at loose-head to Wian du Preez after Horan’s impressive cameo in Galway last week.

It will be equally fascinating to see how Munster’s younger guns go.

The corresponding fixture saw Munster end a five-match, try-less losing streak to Leinster, but after the ensuing Grand Final loss it was Leinster’s turn to gain revenge in the Aviva last November.

Generally, the league meetings tend to go with the home teams and accordingly the bookies make Munster favourites, albeit by a point.

But even the bookies struggle to call this match up. Form, and there’s not much of it lately, tends not to count for much and it’s worth remembering that Leinster were the bookies’ favourites when Munster won the 2006 semi-final and vice versa in the ’09 semi-final.

Traditionally, Munster were usually a bad bet the week before returning to Europe before bucking that trend last season when they won before rounds three and five, and fat lot of good it did them.

This season they lost before rounds one and three, only breaking the pattern before round five when beating Treviso at home.

In other words, they have regained their habit of upping their game for Europe.

True, in their Thomond fortress, Munster’s need is the greater this evening.

Defeat would put them right back in amongst the peleton chasing second place and a home semi-final, while leaving Leinster at least 10 points clear at the top.

Both packs look capable of holding their own in the set-pieces but with Paul O’Connell, Conor Murray and Donnacha Ryan all absent (though given the green light to return to training next week) Munster are not quite at full pitch for this one.

Furthermore, with David Wallace not sufficiently at full tilt to even feature in the 23, the home side are lacking a little ball-carrying ballast up front.

Though rustier, by contrast, Leinster have plenty of firepower from the start and, it has to be said, off that eye-catching bench.

Last six meetings: (2009-10) (Thomond Park) Munster 15 Leinster 16; (s/f RDS) Leinster 16 Munster 6; (10-11) (Aviva) Leinster 13 Munster 9; (Thomond Park) Munster 24 Leinster 23; (final, Thomond Park) Munster 19 Leinster 9; (11-12) (Aviva) Leinster 24 Munster 19.

Leading try scorers: Munster – Simon Zebo 6, Danny Barnes 5. Leinster – Ian Madigan 7.

Leading pts scorers: Munster – Ian Keatley 147, Ronan O’Gara 59. Leinster – Isa Nacewa 108, Fergus McFadden 84.

Betting: 4/5 Munster, 20/1 Draw, evens Leinster. Handicap odds (Leinster +1pt) 10/11 Munster, 18/1 Draw, 10/11 Leinster.

Referee: Nigel Owens (WRU).

Forecast: Leinster to win.