When it comes right down to it, Leinster need the scrum and lineout to do what it threatened to do in Toulon and for Jonathan Sexton to find the accuracy to match his vision.
The Ireland out-half's radar was off course in France from the boot and out of hand too.
No wonder he looked so despondent.
What has not been mentioned is that Sexton went wrong trying to do the right thing.
His decision-making and option-taking were as immaculate as ever. It is the execution that let Leinster down.
Just when Devin Toner was coming to grips with the Toulon lineout, the towering lock was binned for his illegal work at a maul.
Hooker Guilhem Guirado would have been the most relieved man on the field.
Toulon are in dire need of a lineout master to deliver the ball on a plate for their super-star backline.
Of course, Paul O'Connell is on his way back from his torn hamstring quicker than expected. Thankfully, he won't arrive in time for this one.
The Leinster scrum was brilliantly anchored by Mike Ross and the never-say-die attitude of Richardt Strauss.
Finally, Cian Healy looked to be getting back to his best in an all-action output.
The scandalous ruling on his two-week suspension simply doesn't stack up. To charge a man with one thing and find him guilty of another when it has not even been put forth as an allegation is beyond ridiculous.
Anyway, Jack McGrath was as sure and sound as ever when he entered the fray. While he has closed the gap between them, there is no substitute for the explosiveness Healy can bring when he is on song.
It is just that the loose-head has been struggling to cope with the fallout from his fast-tracked recuperation from a serious neck/shoulder injury and the compressed nature of this season.
Mike McCarthy will play his 300th club game, the 60th for his fourth club.
The under-valued second row plays the game right on the edge of reason.
He hits on suspicion in what is an old school attitude to combat. If he is an "old banger," as he suggested last Monday, he is a 'hard banger' too. The first thing Toner has to do is make sure he stays on the pitch for as long as he is needed.
He is the most vital single person in getting to the Toulon maul. He can build on the hard work in the analysis room by climbing inside the head of the 'get-at-able' Guirado again.
Okay, the Toulon back row is a beastly trio, strengthened by the inclusion of Juan Smith to the exclusion of Mamauka Gorgodze.
Leinster have got to move away from their obsession with Steffon Armitage. The exiled England international is going to be a force on the floor. The fact is the Irish had enough ball to get the job done in France.
They just have to use it better.
They have to rely on the physical power of Rhys Ruddock, who is right back to his best, the fundamentals of Josh van der Flier and the all-round excellence of Jamie Heaslip.
The blinding speed to strike from distance is not there and the refusal to look to offloading means Leinster have to pass around Toulon or Sexton has to kick behind them.
The pass-and-catch skills were not accurate enough last week. The is room for improvement there even though it is not a strength for either Luke Fitzgerald or Ben Te'o.
The cross-field kick is an option that can be taken up despite the proficiency of Bryan Habana in that area with Dave Kearney and Isa Nacewa as brave as anyone in the air.
Toulon have only been at their best when they took over Leinster's mantle in that watershed 2013 quarter-final, one dynasty succeeding another.
Since then, they under-estimated them last year and last week due to the evidence of inconsistent and unimpressive form.
This is the chance for Toulon to show they can do on the road what they do at home. Common sense complies. Something in the pit of the stomach doesn't.
Leinster: R Kearney; D Kearney; B Te'o, L Fitzgerald, I Nacewa; J Sexton, E Reddan; J McGrath, R Strauss, M Ross, D Toner, M McCarthy, R Ruddock, J van der Flier, J Heaslip.
Toulon: D Armitage; B Habana, M Bastareaud, M Nonu, D Mitchell; M Giteau, E Escande (capt); F Fresia, G Guirado, M Stevens, J Suta, R Taofifenua, J Smith, S Armitage, D Vermeulen.