There is no doubt Quade Cooper will be piloting the Wallabies' World Cup campaign from No. 10 after his dazzling success with the Reds this season, but can the national team afford to include Australia's two other wunderkinds in the first XV?

James O'Connor and Kurtley Beale were no doubt amongst the first picked for Robbie Deans' 40-man (to be pruned to 30) Wallabies squad, but in contemplating a balanced run on side for the Tri Nations, there will be a legitimate concern over the defensive capabilities of a backline featuring the three phenoms.

Cooper isn't the turnstile he's made out to be, but Queensland did opt to hide him in defence, if for no other reason than to help preserve a bit of energy to launch those match-turning attacking raids. Fullback Beale, meanwhile, is not greatly dissimilar to his mate from the Reds -- an attacking genius who opposition sides wouldn't mind running at if he was in the first defensive line, especially at Test level.

Remember, Cooper slotted in as fullback in defence for the Reds, but swapping places with Beale in the Wallabies doesn't seem a viable strategy.

O'Connor is a tough little nut who probably does more than his fair share of tackling. But the fact remains, he's, well, little. Those very large and frequently angry men from South Africa and New Zealand will relish running at his Bieber-like mug.

Of course, the trio's value to the Wallabies is likely to swell enormously this season: each has the ability to change a game in a heartbeat and in O'Connor's case a goalkicking role could be awaiting. (No less than Grant Fox, the Kiwi goalkicking metronome and pointscoring machine believes O'Connor is the man for that job).

But where do you play him? Inside centre? Maybe, though Deans doesn't seem to like the idea and said as much last week in passing. Instead, O'Connor and his hair will probably end up on what would normally be injured Drew Mitchell's wing.

In all likelihood Matt Giteau will get the gong for the 12 jersey and while he is defensively sound, he's no giant. Even more alarming is the lack of a clear cut, leading candidate for the outside centre role -- arguably the hardest defensive position in the backline.

So potentially the first Test against South Africa in Sydney on the 23rd could feature a backline with a few little guys punching above their weight, a five eighth and a full back with targets on their heads and an inexperienced Test No. 13.

Even the understrength Springboks who have, despicably, opted to leave several hundred of their first choice players at home to recover from, ahem, injuries, will be rubbing their hands in anticipation.

They'll focus wave after wave of attack through the 10-12 channel before glancing up to check where Digby Ioane is then swing it wide, the other way, where a baffled Wallabies 13 - possibly the workmanlike Anthony Faingaa - and makeshift winger in O'Connor will be trying to keep up.

Contemplating what the gigantic and balanced All Black backline will aim to do to our tiny heroes doesn't conjure pleasant images.

On the other hand, the Reds showed what an agile and clever defensive line could achieve in the Super 15. They threatened to crack many times against the Crusaders but largely held firm, mainly by not overcommitting at the breakdown. (Counter-rucking will be a relentless and effective tactic against the Wallabies in the Tri Nations and the World Cup).

Technique and commitment can make a big difference to a team's fortunes in defence - scientists will be studying the Melbourne Rebels for years to come in order to re-write the book on ‘worst practice'.

Deans, no doubt, will have the Wallabies playing intelligently and offering brave resistance, but the cost and reward ledger of having three tearaways in the same backline will make interesting reading after a few Tests.

Perhaps it's essential the trio play together because the way it's shaping they might have to score a lot of tries to keep up with the opposition.