Adam Ashley-Cooper insists Brian O'Driscoll remains as dangerous as ever as the rivals prepare to meet for the first time in Saturday's opening Test between Australia and the British and Irish Lions.

Ashley-Cooper is one of only two certainties for inclusion in the Wallaby backline - scrum-half Will Genia is the second - with the nomadic Waratah having finally established himself in the number 13 jersey.

While he has faced Ireland three times, he played on the left wing and at full-back, denying him the chance to lock horns with an opponent he views as a "soldier" of Test rugby.

O'Driscoll announced himself to the Australian public with his stunning solo try in the opening Test of the 2001 Lions tour and he has been in terrific form since returning Down Under with the class of 2013.

"I disagree that he's not the explosive centre of 12 years ago. He has the experience and ability to keep turning up," Ashley-Cooper said.

"He's a soldier and that's why he's one of the best centres in the world. You can't presume anything with him.

"He's an absolute freak and I'm looking forward to lining up against him for the first time."

The three-quarter duel is being viewed as a battle between the Lions' bigger and more powerful ball runners against the smaller but more elusive Wallabies.

Ashley-Cooper protests at the comparison in size, but expects the tourists to persevere with the bulldozing gameplan that has produced five victories against provincial opposition.

"We're not that small! They do have a big backline though," he said.

"I haven't seen a northern hemisphere side be as expansive as these Lions have been for a while. Their ability to spread the ball has been quite impressive.

"They've come out with a very physical and confrontational approach to the start of the game and then have that ability to throw the ball wide.

"From a backs perspective defending that is going to be tough because first you have to consider their physicality and great ball running forwards, but then have to defend the width they're capable of achieving.

"They've been consistent in the way they approach each game, relying on their big forwards to get over the gain line and create the punch for them, before using the ball out wide.

"George North and Alex Cuthbert - it would be silly not to get the ball to those guys."

Hard running wing Digby Ioane has declared himself fit for the first Test in Brisbane after completing his recovery from a knee injury.

The Wallabies name their team in the early hours of Thursday morning.