Australia has named three debutants for Thursday’s day-night Test against South Africa in Adelaide.
Smith named debutant batsmen Matt Renshaw, Peter Handscomb and Nic Maddinson.
It is the first time since 2011 Australia has taken such a punt on new blood.
"We've obviously made a lot of changes," Smith said.
"I'm happy with the team that I've got.
"This series has been disappointing the way it has gone for us but I'm actually really excited about the young guys coming into the group.
"I've almost felt a little shift over the last few days in attitude and energy from what the new guys have brought in."
Australia face a whitewash after South Africa downed the hosts in Perth and Hobart.
Australia XI: David Warner, Matt Renshaw, Usman Khawaja, Steve Smith (capt), Peter Handscomb, Nic Maddinson, Matthew Wade, Mitchell Starc, Josh Hazlewood, Nathan Lyon, Jackson Bird.
