Rob Herring doesn't subscribe to the theory that Ireland are lacking a "dog" as described by Brian O'Driscoll earlier this week.

The Ulster hooker will win his ninth cap when Andy Farrell's side welcome Scotland to the Aviva Stadium for their opening Guinness Six Nations game on Saturday.

The former Ireland captain told RTE Sport: "I just wonder, do we have that level, in the best possible way, that 'thug' within the team that you want to throw their weight around a little bit and set out a few markers."

But South Africa-born Herring says he can't see what O'Driscoll, who cited the likes of Paul O'Connell, Denis Leamy and Sean O'Brien as examples, is coming from.

"I would disagree with that because I don't really know what it's based on," said the 29-year-old.

"I don't know what he has seen in our club games that makes him think that. Andy has picked a squad that can deliver on that aspect and obviously we have to go out there and do it still."

Scotland have not beaten Ireland in Dublin since 2010 and come in off the back of a disappointing World Cup campaign where they failed to reach the quarter-finals.

New captain Johnny Sexton also believes that his side will be able to bring the required aggression to notch another win over the Scots, following on from the 27-3 World Cup win.

"[Aggression is] the game, isn't it? The fundamentals never change," said the out-half. 

"You need to have that physicality and aggressive mindset and we need to bring that at the weekend.

"I know a lot has been made about [if] we have a 'dog' in the team... but in the modern game you just need guys that are willing to work hard.

"You have to have that intent. We'll hopefully show a bit of that at the weekend."

Herring, who has helped Ulster into the last eight of the Champions Cup, has been biding his time to get a Six Nations game, with the retirement of captain Rory Best moving him up the pecking order. 

"This might be my fourth campaign," he said. 

"I've never managed to get on the pitch so it's been something I've been working towards for a long time now, something I've dreamt about so to be given the opportunity is something special. I've just got to cherish it now and take my chance.

"Potentially [the game time with Ulster helped], in the past I've probably missed out in some of the bigger games for Ulster and that's been one of the reasons I've been given that I didn't get much game time in the Six Nations

"But I've taken a bit of confidence from playing in those bigger games. I assume that's helped. I've really enjoyed the season so far with Ulster.

"I'm enjoying the rugby up there so I feel like I can take that form into the weekend."

Follow Ireland v Scotland (kick-off 4.45pm) on Saturday via our live blog on and the News Now app or listen live on RTÉ Radio 1's Saturday Sport. Highlights on Against the Head, Monday at 8pm on RTÉ2 and RTÉ Player.