Toner is crucial in Blues' bid to take sting of Wasps
Champions Cup, Wasps v Leinster, Live BT Sport 3 (KO 3.15)
It is all about rhythm for Leinster.
In an ideal world, the map to victory laid down by Leo Cullen and Stuart Lancaster will be super-smooth, devoid of any potholes.
Where would the fun be in that? It is the uncertainty about what will happen that will attract people to the Ricoh Arena tomorrow afternoon.
Leinster are hunting the bigger picture of becoming back-to-back champions.
In contrast, Wasps are looking to use Leinster to kick-start the rest of their Premiership campaign.
The fast ball service required from the half-backs Jamison Gibson-Park and Ross Byrne to open the field for their backs hangs on the efficiency of the set-piece.
Enter Devin Toner.
The old school second row with the news school understanding of the lineout has ruled the airways of club and international rugby ever since Joe Schmidt came to power at Ireland in 2013.
He has been Ireland's mainstay of the engine room, even seeing off Iain Henderson, Tadhg Beirne, Ultan Dillane and Kieran Treadwell, since the advance of James Ryan.
In fact, Toner has been predominantly immune from injury right up until last week when a minor ankle problem meant he wasn't available for Toulouse.
"He didn't even know the rehab coaches names," quipped Leo Cullen.
Toner took his seat in the stand of The RDS with the rest of the walking wounded and those unselected to see Toulouse put in their place.
He even had to stomach watching Ryan taking over 'his baby,' the lineout with annoying success.
The Meath man returns to partner Ryan with Scott Fardy dropping to the bench ahead of the intensity of the Six Nations period.
Maybe, just maybe, the veteran will have to cope with the presence of Wasps captain Joe Launchbury in two weeks time at The Aviva Stadium.
"He brings a lot to the team when he plays," agreed Toner.
"He is a very agile lock, he's deceivingly agile.
"He poses a huge threat at the breakdown as well. When he makes a good tackle, he likes to swing around and get back up, get that back-end in."
The talismanic Launchbury is a no-nonsense operator, someone as likely to thrive in the trenches as he is on top of the ground. He never neglects the foundation pieces for a front five forward.
"The lineout and the maul, he's a nuisance defending the maul as well. So, you have to have your eye out for him all over the park to be honest.
"He's going to have a lot to prove as well.
"He's coming back from injury and he brings a lot to that pack."
It is the nature of the beast to reach for reasons to be at your best.
Toner and Launchbury only have to look at each other.