Eddie Jones has labelled the Wallabies the most improved team in world rugby but says his England team will still be smarter tactically in Sunday's Twickenham showdown.
With his pre-match verbal offensive gathering steam, Jones delivered some rich compliments to his former team, declaring the Wallabies were much better now than when beaten 3-0 at home by England in June at the start of the international season.
"Having said all I've said, Australia are probably the most improved side in world rugby," Jones said.
"What they've done throughout the Rugby Championship and then on tour here is quite brilliant.
"Their attack's become a lot more varied, their alignment is better in attack, defensively they're making better decisions and key players have come back.
"Will Genia is a player who I know very well. He's an outstanding player and at his best he was the world's best halfback.
"He's probably not quite there at the moment, but he's playing some really good rugby and adds a solid and influencing role to their team.
"I've been really impressed with what they've done."
While the Wallabies lost the chance to complete a rare grand slam of triumphs over the home nations when beaten narrowly by Ireland at the weekend, Jones warned their motivation would remain sky-high, given the embarrassment they suffered at England's hands in June.
"We don't get a head start because we won 3-0 in Australia. I saw an interesting press conference with the Man City manager Pep Guardiola who was talking about playing Burnley," said Jones.
"Last time Man City played Burnley they beat them 4-0. He made the point - and it's so true - that when you get beaten by a big score the attention you put on the next game against that opposition is more intense.
"You're physically and mentally more motivated. Australia's will to win is going to be enormously high. Our challenge is to make sure our will to win is higher than theirs.
"Tactically we'll beat them but we've got to have a greater will to win than them. We've got to raise our efforts from this week. This is a one-off game against Australia - the 3-0 series win has nothing to do with it."