Michael Cheika, day one in Leinster, made Jamie Heaslip his number eight. Des Dillon was primed to be Victor Costello's successor, but Cheika saw an unbreakable 22-year-old from Naas.

That was the 2005 preseason in Old Belvedere RFC when Leinster operated out of portacabins, with Cheika like a foreman on a pre-Celtic Tiger building site.

And Cheik's a self-made fashionista. Seeds of change were planted that winter; flash forward to preseason 2009 when the newly crowned European champions bid adieu to Rocky Elsom. Cheika, in his ruthless quest for success and tearing down the dominant Munster wall, had a habit of going with proven foreigners over local kids – Isa Nacewa instead of Rob Kearney, Felipe Contepomi despite Johnny Sexton's growing discontent – so we asked about the next international signing to fill the enormous ball-carrying and defensive void caused by Elsom's return home to captain the Wallabies.

“Seán O’Brien, mate. He’s good to go.”

So destructive was this 22-year-old flanker, then as now, that breaking down became the norm. It undoubtedly slowed progress from youths to UCD and into the pro game.

But Cheika had made up his mind. Leinster were operating out of Riverview health and fitness club by then. Stylistic and genuine progress.

“He’s doing all right,” Cheika laughed at Monday morning’s 8am media gathering in the Conrad hotel when asked about the man who will go after his team’s primary strength.

Off-limits

The All Blacks were cooped up in Castleknock, but the Wallabies have chosen the option of being able to ramble around the city centre while training in Terenure RFC (Temple Bar after dark is off-limits).

“He’s a good lad,” Cheika said with affinity to O’Brien. “I tried to get him to go to Stade Français when I went there.” (He did convince Contepomi and Stan Wright.)

“He’s a quality player. I feel for him because he has been hampered by injury over the years but every time he comes back, if he was a race horse first from a gallop I’d tell you he’d be a winner every time, every time he comes back from a period off and just gets into it like he has been playing for six years. Just straight into it. Straight up to the physical side of the game as well.

“He’s a quality player,” he repeated.

Jamie and Seánie; Cheika made them as much as they made the coach.

“I know those boys in the backrow. It’s been a while but I know the quality they will bring.”

Opposing forces on Saturday will be the Wallaby backrow from last year's run to the World Cup final – the devastatingly effective Zimbabwean-born David Pocock, unsung Scott Fardy and Michael Hooper (fresh after being rested for the 25-23 victory in Paris that keeps the grand slam on track).

Five turnovers

The statistics pouring out of this trio give them a chance in any test match. They clocked up five turnovers in the Cardiff rout. Pocock and Hooper combined for 24 tackles in the one-point squeeze at Murrayfield. Pocock took down 18 French men on the weekend but worryingly coughed up three penalties.

They, admittedly, have not paid much heed to Ireland – "Seen a lot of headlines," said Hooper – but the name O'Brien rings out all over the world.

“[I’m expecting] more of what he has been doing,” the openside continued. “Very impressive player, times I played him he’s been great.

“I’ll be looking at what he’s been doing in the past few games in more depth and potentially where he can hurt us.”

The war of lowest shoulders over the ball is guaranteed.

“There is no secret we want to play with fast ball.”