Dog.

The terms ‘dog’ is regularly used in rugby and is the definition of someone who is not afraid to get stuck in and play to the very edge – both in matches and in training!

He’s not afraid to rustle a few feathers and he’s the kind of guy that can raise the intensity of an entire team with one action. And that’s exactly what former Ireland and Leinster back-rower, Sean O’Brien was.

O’Brien has built up a reputation over the years as the ultimate ‘dog’ in training and in matches. And it turns out it’s not something that evolved with his game, it’s something that he had in him from the minute he set foot in the door at Leinster.

The 34-year-old has previously told us that not coming through the traditional system and coming in from the club game instead played a role in sparking that fire within him. Former teammate Shane Horgan knows Seanie all too well and chatted about his early days at the eastern province on this week’s episode of House of Rugby.

“He tells all the stories himself, he rats himself out,” Horgan joked when Alex Goode asked him to spill the beans on O’Brien who is a regular on the show.

“Ah listen, Seanie was an absolute breath of fresh air when he first came into Leinster. He was always a bit of a ‘dog.’

“But I remember I got tapped up by the coach at the time, who was [Michael] Cheika, who was tough on him, super tough on him because he knew how good he was. And Alan Gaffney I think was our backs coach.

“At the time we had this really weird training area where we would have some of the academy lads in and about. And Seanie was bouncing around, I didn’t really know who he was, and I got pulled aside from Alan Gaffney and he said ‘this guy is the real deal, he’s gonna be in this squad soon, keep an eye on him.’

“I said like, ‘is there any plans to bring him in?’ and he had his hand in a cast [at the time] and [Gaffney said] ‘we can’t get him in because he keeps on breaking his hand off peoples’ heads!’

“At underage level, he broke his hand off a fella’s head in an u-21 game, healed up, came back, broke his hand off someone else’s hand a couple of weeks later!

‘And then when he came into [senior] training he did not hold back! He was one of those guys that you knew he wasn’t going to take an ounce of a step back from anyone, even as a 20/21-year-old against older, well-established internationals.

“He was straight into the mix, throwing haymakers. And he never stopped! He’s still doing it now just in a different way!”

Goode added that even at 34 and in the twilight years of his career, O’Brien is still as feisty as ever.

“One of my mates at London Irish said he’s still one of the number one guys to get in scraps at training!” Goode said.

“He’s always there.

Horgan added that that ‘doggedness’ is vital for any team that wants to be successful.

“You need a little bit of ‘dog’ and you need it in training as well. Our best training sessions were when there was a few punches thrown, definitely!” Horgan added.