Conan is determined to seize opportunity and prove he can make big contribution
Jack Conan is not his usual self, which is a good thing. He's usually bubbly; now he is becalmed.
He looks and feels focused, assured. The Leinster player knows he has not always been the player others reckon he could be.
More importantly, he knows he has not always been the player he knows he could be. Now is his chance, however fortuitous, to make his mark.
For Conan's part, Joe Schmidt has told him before about the "mental tap-outs" he would have during games; he knows now he must keep the tap running. Physical and mental inattention must be replaced by intention.
"It's a massive opportunity for me," said Conan, who replaces the injured CJ Stander in a back-row which has also seen the de-selection of his club colleague Josh van der Flier.
The absence of Grand Slam-winning colleague Dan Leavy, not to mention an occasional Irish captain Rhys Ruddock, as well as Jordi Murphy, illustrates just what a golden opportunity this is for someone who hasn't always convinced in his rare international outings.
"I've been waiting in the wings for so long and I probably haven't performed at certain times. That day I came off the bench against Wales last year, I made a defensive error and let them back into the game," he said.
"The margins are small at Test level so you just need to be at your best. I'm excited, I'm looking forward to the weekend and it's going to be a massive test.
"I'm focused, I know what I have to do, I know the role that has been given to me. Now it's just about executing and bringing that physicality."
Schmidt reckoned his side were bullied and man-handled; he is seeking a response.
"I suppose he said that to probably spark a reaction in us," conceded Conan. "No one likes the thought of being bullied. At times we might have been physically bested but I think it's the word that's going to stick in everyone's head this weekend and we're just going to make sure it doesn't happen again.
"When you break it all down, rugby's a simple game. Carrying the ball is one of my best attributes. It's what I feel I've been put into the team to do, make sure we are getting over the gain-line and winning collisions.
"I don't think what I do has to change at all."
Eleven matches in three years reflects his status in the pecking order, perhaps, for club and country; other, better players have blocked his path and, when he has been allowed to walk on it, often it has been with an occasional stumble.
"I've been in a tough position for the last few years, there is such quality around the back-row position," he said. "It's just about taking your opportunities. You can't look anywhere past what's in front of you.
"The time you do get to put on the jersey, you need to make the most of it.
"But I've been in high-pressure situations and played in big games before, that last Test in Australia during the summer when we clinched the series."
Tomorrow, he is a stand-in for Stander but his mindset must be to stand out.
"Yeah, absolutely. Injuries happen. I'm probably only starting because CJ took a knock and is out injured. I'm just here to make sure I don't let the lads down and I do the best I can," he added.
"I feel like I'm at the peak of my powers. My body feels fit and ready to go. Once I have that confidence, it's just about going out and playing."