Out of the Ireland side since February, the 30-year-old full-back, once a mainstay of the national side, had been through a challenging 18 months beset by injury and poor form that he admitted left him in a dark place.
It also left a number of critics wondering what he done to earn his 70th Test start for Ireland against the All Blacks at Soldier Field last Saturday, with Jared Payne and Simon Zebo both more than eligible candidates to pull on the green number 15 jersey.
Yet head coach Joe Schmidt had maintained his faith in the talents and experience of Kearney, who in return confounded the naysayers.
It was the full-back who provided plenty of attacking spark for Ireland in their greatest victory, a five-try defeat of the world champions to end an 18-Test winning streak and a first win over New Zealand in 111 years at the 29th attempt.
He also displayed the aerial prowess that earned him that earned him plaudits as one of the best full-backs in the world.
Had he shown people?
“Yeah, ish,” Kearney conceded.
“There were still a few mistakes out there.
“It’s been a tough enough 18 months. Just, first and foremost, body has not been where it was been.
“Then on the back of that, you’re not playing to your potential and people get on your case, then you get on your own case.
“Inside my head has been a dark enough place in the last few months.
“I wasn’t sure if I was going to be selected this week, and I’m just glad I was able to repay Joe and my fellow players the trust that has been shown. But there’s still lots of stuff to work on, it wasn’t a perfect performance by any means.”
Schmidt and Kearney go back a long way, since the New Zealander joined Leinster as head coach in 2010.
They have won Pro12 titles, Heineken Cups and Six Nations Championships together and when the going did get tough for the full-back he was appreciative of his coach’s faith in his abilities, even if he showed it in a less than orthodox way this week.
“He pulled me aside before the game and he said, ’You need a big one today’,” Kearney revealed.
“It wasn’t ideal, but it was good.
“We’ve been together a long time now from when he first came to Leinster.
“So maybe that was the one-liner that I need to put the fear of God into me.
“He (placed) a huge amount of faith. I was glad to be able to repay it a little bit. I’m sure he’ll have lots of things for me throughout the week - a few missed tackles and some coverage in the backfield, might have got caught out once or twice. He did show a lot of faith.”
Against the All Blacks in Chicago, Kearney rediscovered his form and confidence at the ideal moment.
“It’s been tough. I tell you how I got my confidence back - it was one high ball and one linebreak. I’ve been waiting for a spark, something like that, for so long and this week I just said, ’don’t wait, just go try and make something happen with the shackles free.’
“I’ve been in those moments before and things haven’t gone your way. So I won’t get carried away by any means, but it’s nice to be back on the horse a little bit, for how long I don’t know.”
He could be speaking for the Ireland team but again, Kearney pointed to the collective’s growth since an equally dark moment against the All Blacks in November 2013.
“It was unbelievable. When they got their few tries (in the second half to close the gap to 33-29) and they had their purple patch, we came back under the sticks and... we were right back in the Aviva in 2013 when we were under our sticks after losing the game.
“You learn from those experiences and I think we played and went to the edge once, and Zeebs (Simon Zebo) kicked that ball down the line (in the build-up to Robbie Henshaw’s 77th minute try). That was a huge play, whereas maybe back in 2013 we would have just kicked off first phase and let them come back at us.
“It’s little intricacies likes that that you can’t see them from the spectator watching, but to us it was a big moment in how far we’ve come maybe.”
It was a defining point in may ways and all in a week when Ireland followed in the footsteps of hometown baseball heroes the Chicago Cubs, who ended their own hoodoo by claiming a first World Series in 108 years.
Kearney referenced that and also Ireland’s own cursed 111-year history of misery against New Zealand.
A first victory, he said was “not just about this team. It’s about the 28 teams that have gone before us. We’ve been waiting a long time to defeat the All Blacks and it is such a difficult feat. We really gave everything today and we really deserved it.
“After the Cubs during the week, there must have been something in the air in Chicago.” Not that Ireland will be allowed to celebrate for too long. As Kearney suggested, Schmidt will have his players back to the grindstone soon enough.
Some of Saturday’s bench and wider squad members will get their chance against Canada this Saturday in the first of three Guinness Series Tests this month at the Aviva, with New Zealand returning to Dublin the following week.
“They’ll be back, they’ll be wounded,” Kearney said. “They’re a class side. Their lineout was not functioning really today and they had a fair few handling errors. We’re under no illusions what’s coming back.”