The flanker suffered a serious tear to the muscle during Ireland’s Six Nations game against France in Paris last February and subsequently underwent surgery in early summer after an initial attempt at rehab failed.
The good news is that his recovery is on track and maybe even a week or two further down the line than anticipated at this point. Back running with the squad this week and next, he should be in contact the week after that.
It’s welcome news for a man who has undergone close to 20 surgeries in the course of his career and it puts him on course for a return on October 23, when Leinster visit Montpellier for their second Champions Cup assignment.
Only a home PRO12 tie with Connacht separates that French date from Ireland’s appointment with New Zealand in Chicago but not even the all-conquering All Blacks will tempt O’Brien into a premature return this time.
“This is my career as such, it’s not about getting back for a game. This is about me wanting to play rugby for the next four or five years. There’s no point me going back a week before I should because that is goodnight then.
“That is basically what it would be if I tore (the hamstring) again so I don’t think there would be another option,” the 29-year old added. “That’s why I am taking my time, why there is no deadline. That’s just the way it is.”
A younger O’Brien would not be so patient. He admits to having rushed himself back too soon in the past but the Carlow man is at a point in his career where he needs to think strategically and act smart given the litany of injury issues in recent seasons.
He managed just six games for Leinster last term and he has missed 20 of Ireland’s last 32 tests. His profile since breaking a shoulder against Ulster in December 2013 has been, frankly, devastating.
People have fretted for his career. He understands that.
“Of course I do. Sure I have had that myself. I would be lying if I didn’t think about it. When I did the rehab and came back and then it wasn’t good... it was just a very unusual tear that I had. It was a little bit trickier, in terms of the way it had to be repaired and stuff.
“That was the worrying part for me but literally a week after the surgery I knew it was different already, I didn’t have any more pain. There wasn’t a flinch out of it. Thankfully, that worked and I could get the head down and start working towards where I am now.”
His problem isn’t just injuries but the seriousness of them. Strains and niggles aren’t his issue. When Sean O’Brien gets injured, he really gets injured. Breaks, tears, the sort of problems that involve months rather than days or weeks.
Who knows the effect it will all have on the rest of his career? You could argue the wear and tear will shorten his time on the paddock or suggest that, like Paul O’Connell, the extensive absences from it could actually allow him to extend his playing days that bit further.
Whatever the time left, his approach won’t change.
Like Cian Healy, who has suffered similarly with fitness issues, O’Brien’s worth to Leinster and Ireland is predicated on an all-action explosiveness that is rare in an Irish forward. It is his calling card. His stock in trade.
There will be no deviation from that. “It definitely is the way we play the game. That’s what makes us the players we are. It’s probably the breakdown and the tackle where we do most of our damage, how we fire ourselves into the middle of the breakdown.
“Lads are getting free shots on you. If I take 10 shots in a game, for instance, but I get three turnovers, that’s a great thing. If I take 15 shots and get no turnovers, I’m doing something wrong. It is the environment we’re in and that’s the way we play.”