THERE is no time to waste for Leinster's trickle-back trio of Brian O'Driscoll, Rob Kearney and Luke Fitzgerald as they bid to transform the recent form guide.
The problem is that the workhorses up front have to provide the platform for the fleet-of-foot in behind. A pack without momentum is about as useful as an Audi A4 stuck in neutral.
The lineout has to be streamlined. This is where the brains of the operation, Leo Cullen, will step forward to command an area he has long mastered.
The scrum has to be stable and generate forward motion. This comes under the remit of scrum leader Mike Ross, a self-confessed nerd when it comes to this most technical and physical area.
The breakdown has to be as clean as a baby's backside so that the incoming scrum-half can whip the ball away at speed. Eoin Reddan has been chosen for speed of service.
Coach Joe Schmidt has also gone for the extra lineout option and hard-hitting of Kevin McLaughlin around the edges in the back row ahead of the more cerebral skills of Shane Jennings.
Even then, the expectation that three players who have played a total of 439 minutes between them this season will trigger a rush of tries is simplistic and unrealistic.
Worse again, the vast majority of that game time has come from the limbs of Ireland captain Brian O'Driscoll. He should be sharper than the other two.
First and foremost, Leinster have to show more than a glimpse of the quality that has separated them from all challengers in Europe for three of the last four years.
It all begins in Edinburgh. Leinster have not exactly been themselves. A three-game losing streak was halted in an unimpressive 17-0 defeat of Connacht at The RDS last Saturday.
There is light. Leinster have won their last four encounters with Edinburgh and have won on two of their last three against Edinburgh at Murrayfield.
The Scots have lost out in the last four matches in both the Heineken and the PRO12. Their last victory of any kind came in the last week of November, a half-a-dozen games back.
Edinburgh: G Tonks; D Fife, M Scott, B Atiga, T Visser; P Francis, G Laidlaw (capt); A Jacobsen, A Titterell, W Nel, G Gilchrist, S Cox, S McInally, D Basilaia, D Denton.
Leinster: R Kearney; F Carr, B O'Driscoll, G D'Arcy, L Fitzgerald; J Sexton, E Reddan; C Healy, S Cronin, M Ross, L Cullen (capt), D Toner, K McLaughlin, S O'Brien, J Heaslip.