It hurts more when the expectation levels are so high and with a potential final day shootout against age-old rivals Munster in the offing in their own backyard, that sense of disappointment is as acute amongst the supporters as the players.

With three defeats in their last four games, Leinster’s season has imploded in a manner nobody would have foreseen after their 32-17 demolition of Aviva Premiership finalists Wasps at the quarter-final stage of the Champions Cup.

Once again we see the importance of having a hardcore leadership group down the spine of a team. Leinster have introduced a raft of quality young players to the mix over the last two seasons but to prevail at the business end of the season, having wise heads and calm decision makers is a necessary ingredient.

That is why Leinster’s initial selection for Friday night’s semi-final surprised me. Already short Jamie Heaslip from the back row, why would you name a Lions tourist in Sean O’Brien on the bench? If he was fit enough to be included there, he should have started.

The same logic applied to Devin Toner. Scarlets have been scoring tries for fun lately, all the more reason why you had to cut off the supply line and seek to smash them in the setpiece and at the breakdown. Leinster did neither and paid a huge price.

Their tactical naivety, with a half-time debrief available to them to contemplate how to best expose a side reduced to 14 men, was also stark.

The Leinster management will have much to ponder over the summer months.

The question now is whether Munster can absorb the lessons of Leinster’s failure and put them to best use against a Scarlets side that is thriving on the more favourable playing conditions that prevail this stage of the year.

In contrast to Leinster, the Scarlets have hit a rich vein of form and are now on a six-game winning streak going into the final. Their offloading game is sensational and their ability to convert turnovers into points will have Munster on red alert.

It took Munster a long time to deal with the admittedly negative approach the Ospreys brought to the second semi-final at Thomond Park but eventually, spurred on by a magnificent try from Simon Zebo on 61 minutes, Munster found their way.

When you consider Scarlets dismantled the Ospreys with contemptuous ease in a 40-17 hammering of their near neighbours in the final round of PRO12 action a few weeks ago, you get a measure of the challenge facing Munster, despite the advantage of having it at the Aviva.

In terms of bums on seats, the tournament organisers would have preferred an All-Ireland showdown but, having hosted that already in Edinburgh last season when Connacht prevailed over Leinster, it is better for the competition as a whole that a Welsh side has progressed to the decider.

The fact Scarlets play such an attractive brand of rugby should also help in luring neutrals to the game.

Facing Leinster in a final in Dublin would have suited Munster’s mentality just fine but, if they fail to get their heads around the threat Scarlets bring to this one and are slow out of the blocks, they will be in trouble.

It was Munster’s failings in their attack that ultimately scuppered them in their last appearance at the Aviva Stadium, against Saracens in the Champions Cup a few weeks ago.

They found it impossible to breach the famed Saracens defensive blanket that day, yet to win this one Munster will need to score tries on the basis that, on current form, you would expect Scarlets to score a minimum of two themselves.

Therein lies Munster’s dilemma. It was confirmed during the week former All Black Francis Saili had lost out in his individual battle with Jaco Taute for the one overseas contract available to Rassie Erasmus in midfield.

Taken on the season as a whole where Taute’s impact especially in defence, despite the fact that he has also scored eight tries, has been greatest, you can understand Erasmus’s choice.

Yet again last weekend, as he showed when introduced in the second-half against Saracens, Saili looked the Munster player most capable of making line breaks.

All too often however, it is what he does after those breaks that defined his season. Too often we have seen him attempt the million dollar pass or a failure to retain possession.

In Super rugby back in New Zealand, he is used to support runners immediately flooding his channel on the back of those breaks, enabling greater continuity and try scoring opportunities.

Munster haven’t been able to achieve that and it will be interesting to track Saili’s impact and influence when he moves on to England or France which appears inevitable.

I hope Munster won’t be left regretting that decision and that new signing Chris Farrell can deliver on the rich promise he has shown for Grenoble in the Top 14.

Given Munster’s hunger for silverware it is hard to imagine a scenario where they will be as mentally off the pace as Leinster appeared last Friday.

Seven years is a long time to go without success and to win the Guinness PRO12 after the back-up squad captured the B&I Cup would work wonders for what happens down the road.

Munster’s limitations in attack were there for all to see against Saracens but it will be a measure of the team and coaching staff as to how they go about minimising those on Saturday and capitalise on their strengths of which they have many.

In many ways Saturday’s final will be a battle of contrasts as Munster pitch their set piece strength, excellent maul, strong kicking game and outstanding defence against the attacking prowess of a Scarlets back line, led by the magnificent midfield combination of Scott Williams and Jonathan Davies and supplemented by a cracking back three in new Lion Liam Williams, former Canterbury Crusader, Johnny McNicholl, and the ever improving Scott Evans, if available after his red card against Leinster.

It may not be the decider that most expected only a week ago but should prove equally intriguing nonetheless.