London - Australia head coach Michael Cheika has warned James Slipper he must prove he can make a valuable contribution to the team's youth revolution.
Cheika is ushering in a new era for the Wallabies and Slipper could be one of the casualties after being left out of the match squad to face Argentina at Twickenham on Saturday.
Australia have endured some growing pains as the youngsters bed in, with six defeats in eight Tests since last year's Rugby World Cup final.
But Cheika is sticking to his guns and Waratahs' 22-year-old prop Tom Robertson has been preferred to 27-year-old Slipper, who has 82 caps, among Australia's replacements this weekend.
"It's definitely a tough call for James," Cheika said on Thursday. "But we're really trying to be diligent around rebuilding the team, with the discipline and detail of everyone's role.
"Other players have missed out because of that and discussing with James he needs to improve parts of his game that aren't up to the standards that he has.
"I want him to go beyond those standards that he's set for himself in the past.
"And sometimes that's going to create a contest with young players coming up behind you.
"Tom has played loosehead in the past. We need to have a flipper in there as well, a prop who can play both sides.
"We feel he's a player who can fill that role so we've been working towards that.
"I don't think Tom Robertson would have imagined he would be ahead of James Slipper at the start of the year."
Robertson's elevation ahead of Slipper acts as a symbol of Cheika's latest Wallabies revolution, with the former Leinster boss adamant he is taking the right path by handing younger players chances to impress.
Cheika insisted Australia must forget entirely their run to last year's World Cup final, where New Zealand prevailed 34-17.
"I think it's pretty clear we're going through a generational change," Cheika said.
"There are nine different players in the side for Saturday from that Rugby World Cup final team, and four or five on the bench.
"We understand that our challenge in Australian rugby is to build more depth and we're going to do that.
"But we're not going to cry about it, talking about losing players overseas. We won't whinge about a lack of depth - we'll go out and make that depth instead.
"That said, winning matches is still what it's all about. No one cares about second - I can't remember who was in the World Cup final, I only remember that New Zealand won it.
"I really believe this is the way to go, it's the right thing to do, I don't know if takes guts or not, it's just what we've go to do."
England whitewashed the Wallabies three-nil on Australian soil earlier this year, but Cheika believes his team should have won all three matches and are still a potent force.
"Against England we had two games where we scored more tries than them and still lost," Cheika said.
"We were outplayed in the two games against New Zealand, but aside from that we could have won the others.
"I'm not looking to say that's any excuse for losing games, it's not.
"But we've solved our defensive issues, so we're getting there.
"We've had a lot of heat thrown our way in different directions and we've dealt with that, so I'm proud of the lads."