Australia's Will Genia is wary of the threat posed by Wales' Gareth Davies, believing the scrum-half to be among the finest at this year's World Cup.
Until a foot injury to Rhys Webb in Wales' final warm-up fixture with Italy, Davies appeared unlikely to be so vital to coach Warren Gatland's plans.
The experienced Mike Phillips was called up as a consequence of Webb's withdrawal and was expected to start instead of his younger compatriot, but Davies has impressed in Wales' three Pool A victories so far.
Genia, who will start at scrum-half against him at Twickenham on Saturday, is among Davies' admirers.
"He's probably been one of the best half-backs of the tournament so far," said Genia.
"He's played really well. (He's) obviously been under a lot of pressure, coming in off the back of Rhys Webb being injured, and performed really, really well.
"I've enjoyed watching him play and we've just got to make sure defensively we're really good around the rucks because he's a good runner of the ball as well.
"(Wales will) do their best to try and slow any quick ball that we can get, and I guess look for turnovers as well. Guys like (Sam) Warburton and (Justin) Tipuric and (Dan) Lydiate are very, very good over the ball so the breakdown's going to be a big area.
"(Gatland's) sides are very, very well drilled. They know exactly how they want to play and what they want to achieve in certain parts of the game, and they work very hard towards doing that.
"He just seems like someone whose attention to detail is a very, very big thing. He had success with that (2013 British and Irish) Lions series and plenty of success with Wales as well. (He's a) very good coach."
Stephen Moore will again captain Australia on Saturday and, in a week in which tournament hosts England - following their elimination - have been criticised for being too predictable and apparently unable to think for themselves, revealed a belief that the independence given to he and his team-mates by coach Michael Cheika has been key to their success so far.
"I'm not that big on having rules," said Moore. " I think you let everyone make their own decisions and, I guess, try and educate them about what the best thing is to do for a high-performance professional athlete.
"The boys have been really good around that side of things and I think Cheika makes it clear what's expected.
"We all know what we stand for, and in terms of curfews and rules we haven't done anything like that, so that's given the boys a chance to make their own decisions and that's a good way to operate."
Source: PA
