Head to Head: O'Brien v Warburton

Two new faces on the international rugby stage who have both made a major impact at the World Cup are the openside flanks for Ireland and Wales - respectively - Sean O'Brien and Sam Warburton. And on Saturday they will go head-to-head in the 2011 RWC quarterfinals.

The O'Brien-Warburton match-up could be the difference between Ireland and Wales, because they have both been so influential in their respective teams' success at the 2011 World Cup thus far.

One man who knows a thing or two about being on the side of the scrum is one of South Africa's finest openside flanks, Rob Louw.

The Western Province legend has taken note of all the best opensiders at the World Cup and has been particularly impressed by new Wales captain Warburton.

"We took notice of him very quickly because of how well he played against the Springboks. Wales seem to have found a star there," Louw told this website.

"Warburton has been very good and he's different to your more common openside flank because he is such a tall guy and still makes an impact on the ground."

The new leader of Welsh rugby, who turned 23 this week, has taken to the mantle of captaining the side and stepping into Martyn Williams's boots will ease it seems.

"He is well spoken and a benevolent kind of guy who has also been excellent captaining the side and you can see that's made a difference for Wales," Louw added.

Ireland have unearthed an almost unknown ace in O'Brien - who, in combination with Jamie Heaslip and Stephen Ferris - is part of one of the strongest, and balanced, loose trios at the World Cup.

O'Brien wasn't even included in Ireland's first match against USA, with Shane Jennings wearing the No.7 jersey, but since then he has been outstanding against Australia, Russia and Italy.

However, Louw believes that Ireland are still weakened with O'Brien in the side and are missing injured first choice openside flank David Wallace.

"Wallace was injured just before the World Cup and I rate him very highly, so I think losing him was quite a blow for Ireland and we could see why in the quarterfinals," he explained.

"Experience is so important because come quarterfinals it becomes the guy who has been there before that is of utmost importance. O'Brien is still so new to this level.

"I'm not convinced he is best suited to playing at openside and he likes to carry the ball, so he might find himself moving to blindside (permanently) one day," added Louw.

When comparing some the best fetchers in the world, Louw is convinced there is one man who is setting the bench mark for all others to follow.

"Neither Warburton nor O'Brien are as effective as Heinrich Brüssow. But all the openside flanks in the world know, that I think, and that includes the likes of David Pocock and Richie McCaw.

Statistical comparison - Sean O'Brien v Sam Warburton:

O'Brien (24 years old):
Total minutes played: 219
Matches played: 3
Tries scored: 1
Tackles made: 30
Tackles missed: 2
Off-loads: 3
Turnovers won: 3
Penalties conceded: 2
Total running metres: 204

Warburton (23 years old):
Total minutes played: 292
Matches played: 4
Tries scored: 1
Tackles made: 57
Tackles missed: 7
Off-loads: 2
Turnovers won: 2
Penalties conceded: 2
Total running metres: 156

Rob Louw's verdict: "Warburton is something special and has been a good leader as well an impressive openside and O'Brien isn't there yet."

Our verdict: "Warburton is a massive talent and does seem to have made an incredible difference in the Welsh side, but we're not convinced O'Brien should be written off in the battle at the breakdown."

By Timmy Hancox