Schmidt: This is going to be a huge struggle
Cotter keen to leave his mark on Scotland
The battle lines have been drawn out. This must be the closest thing Joe Schmidt will get to playing against his big brother in the back garden - bloody big garden, mind you.
Scotland's Vern Cotter is the man who brought Schmidt to the northern hemisphere to complete the change of a losing culture at Clermont-Auvergne.
They made beautiful music together in France and leaving must have been such sweet sorrow.
When the time came for Schmidt to have the 'buck' stop at his desk, Leinster, on the advice of Isa Nacewa, made their move.
Now, the 'brothers from another mother' reunite on opposite ends of the battlefield.
For something close to two hours, they will put friendship in the locker and their men will do what they have to, to get across the line whether for four or five points.
Schmidt has had to summon forth Paddy Jackson, Iain Henderson and Keith Earls relatively late in the build-up.
These are men well-versed in Schmidt's ways and the means by which the coach will look for a third championship in four years.
"I think you have quiet confidence all the time because you know how hard the players work," he stated.
"You know how collective they have been in their endeavour. They are going to try and express themselves as best they can on the pitch.
"You take confidence from that. You know you will get maximum effort from them. Is that going to be enough? We can't be sure.
"That's what people want from a championship. They want games where they're not quite sure because, on any given day, one side can beat the other.
"I would rather have the cakewalk. I know that's not going to be the case.
"There's going to be a lot of games in the championship just like this one where people will really struggle to pick an outcome."
This was the cue for Schmidt to talk up Scotland. "I think they really are that good and they match up man-for-man.
"It's going to be a great game of footie," he added. They've got really complimentary back-rows.
"They've got the power of Josh Strauss. They've got the athleticism of Ryan Wilson. They've got the speed of Hamish Watson. There is balance there and there is balance with the Gray brothers in the middle row.
"I don't think I need to talk them up. It is pretty self-evident when you see what Stuart Hogg did to us last year, what Tommy Seymour continues to do and the athlete that Sean Maitland is."
Ireland's last win away from Dublin in the Six Nations came on their last visit to Murrayfield when a final day blitz of tries secured back-to-back championships.
They are hunting their fifth successive victory over the Scots since their last loss to them in Edinburgh (12-8) in 2013.
And the boys in green have lost their opening match just once since 2004 when Wales raided the Aviva 23-21 in 2012.
Cotter has made three changes from their last outing in the Autumn.
Centre Huw Jones has recovered from the foot injury that prevented his inclusion against Georgia at the tail-end of November.
He made an immediate impact to become the first Scot to bag a brace against Australia on his debut.
Keith Earls' friend Fraser Brown will return at hooker ahead of centurion Ross Ford and Josh Strauss will slot in at number eight, forcing a back-row reshuffle as Ryan Wilson switches to the blindside.
"Facing Ireland first up doesn't get much harder," Cotter let it be known. "They are at the top of their game and will come here with confidence after beating some of the best teams in the world, including the All Blacks and Wallabies and having won the tournament twice in the past three years."
Scotland have lost only once since the end of the 2016 Six Nations and that was one they should have won going down by one point to Australia.
They will not be short of form or confidence from Glasgow's qualification for The Champions Cup quarter-finals for the first time.
They have nine starters and four more off the bench.
There is a familiar ring of optimism about Cotter's intentions to take the game to Ireland in much the same way Glasgow would to anyone.
"We have a number of different options that allow us to continually attack the opposition, which is our main focus.
"We aim to win every game we play but know that Ireland will come here with a lot of confidence and try to dominate us on our home paddock," added Cotter.
"Those are the challenges of the sport at a high level but we'll embrace that and put everything we have into getting the right performance and result this Saturday."
Scotland: S Hogg; S Maitland, H Jones, A Dunbar, T Seymour; F Russell, G Laidlaw (capt); A Dell, F Brown, Z Fagerson, R Gray, J Gray, R Wilson, H Watson, J Strauss.
Ireland: R Kearney; S Zebo, G Ringrose, R Henshaw, K Earls; P Jackson, C Murray; J McGrath, R Best (capt), T Furlong, D Toner, D Ryan, CJ Stander, S O'Brien, J Heaslip.