A multitude of injuries had kept him sidelined during an epic season for both Leinster and Ireland and led some to wonder whether the 31-year-old’s battered body could make an effective comeback.

“I’m not surprised,” Schmidt said yesterday, “he’s a stubborn man and once he’s made his mind up about getting back to where he needs to be, he commits fully to things and all I can say is we’re delighted to get him back on board.”

O’Brien did not take offence at the description of him by the Ireland head coach but embraced it.

“I’m stubborn in terms of I know what I want to achieve in my career,” he said. “Obviously, going through what I’ve done in the last year, I suppose I’ve assessed where I am and where I want to be. Starting from now and in the future.

“I’ve set myself little goals and I don’t want to take a step back from that.

“I want to keep building nicely.

“That’s the stubborn part, where I won’t give in to it. I want to get back to being one of the best players.”

O’Brien may be one of the best players around but he has also missed significant moments of which he would have been a part but for injury, including the 2015 World Cup quarter-final loss to Argentina, the historic first victory over the All Blacks in 2016 and last season’s Grand Slam as well as Leinster’s European and PRO14 double.

Yet, he takes a forward-facing view of missed opportunities.

“There’s loads of stuff like that drives you on and, again, everything the lads did last year, the same opportunities are there again, to go and repeat that, or get to that level again and that’s something I want to strive for.

“It’s just part of my DNA sticking it out and getting back at it.

That’s just the environment we’re in. That’s the life of a professional sportsman. You have to get on with it. I can’t keep saying, ‘oh, I missed out on this, I missed out on that.’ I have to look forward.

“Obviously, you have mixed emotions when there’s stuff that happened, like last year. You are so happy for the lads, the effort they’ve put in because you know what they’ve done to get there, how hard they’ve worked, the hours they put in every day. Then, to finally get to that place is brilliant for them.

“Obviously, you are disappointed as an individual that you have been injured and you do miss out on those big days. But, that’s just a part of it.

“There’s plenty of lads that have done that. I have probably been more unlucky than others missing out on big days.”

And when they come around again, O’Brien believes he must cherish them, lest the next injury be a career-ending one.

“I definitely think over the last year, I suppose, I realised how important it is to enjoy every opportunity you get in this environment and even the province.

“It’s making the most of the time you have. That is probably the thing I’ve been telling myself, to make sure you go out and do your best every time.

“That probably makes it even more special.”

Schmidt, his coach at Leinster and then Ireland for the past eight years, believes O’Brien is “up-and-running” following his recent return to action and the player appreciates the trust shown in him by his long-time boss.

“Yeah, Joe knows me a long time now. I suppose that trust factor is there but I have to show him and the rest of the coaches that I’m back to that level again.

“I don’t know exactly what he said but I suppose it’s about me proving to them that I still have it at this level, am back fully fit and ready to rock.

“I’ve had a great week’s training, it’s been very sharp and I’m in a good place now and it’s just about going out and performing.”