The Leinster star is being seen by some as the perfect payer to come off the bench after his hopes of wearing the No7 jersey against the Qantas Wallabies were seemingly hit by Sam Warburton's appointment as tour captain.
O'Brien has spent his last 15 internationals for Ireland on the openside flank but has also played blindside and No8 at the highest level. And now he hopes that versatility will be a help and not a hindrance as he targets Test selection on his debut tour.
"It wouldn't be my view to be an impact player," O'Brien told the Irish Times.
"No, it would be my view to start and that's what I'll be hoping for.
"I'm going to back myself against whoever is out there and that's always been the way I've been taught.
"I'm saying at the minute that I can play all three positions and that's the way I'm going to stay.
"I'm not going to say, 'oh I can't play eight because the two lads are there (Jamie Heaslip, Toby Faletau)', so there are options there all over the place.
"Sam is captain but I think in any tour if someone isn't performing or picks up a knock there are obviously opportunities. I have to put myself in the best possible position so that if that role pops up then I'm ready to go into it.
"I'll be pretty determined to go about my business over there and try and make the Test side."