Spinner Jon Holland and potential debutant Jhye Richardson have been included in Australia's 15-man squad for the upcoming tour of South Africa.
Selectors retained the side that sealed a 4-0 Ashes win over England in Sydney earlier this month, while adding Holland and Richardson to the touring party for the four-Test series, starting in Durban on March 1.
Victorian left-armer Holland only has two Test appearances to his name, having not played since August 2016 and he is expected to provide backup for leading spinner Nathan Lyon.
The 30-year-old has taken 11 wickets in two Sheffield Shield matches this season, having claimed 50 last term.
"Jon was the second leading wicket-taker in the Sheffield Shield last season and has performed well in the games he has played for Victoria this season," national selector Trevor Hohns said.
"We envisage the wickets we will see in South Africa will not warrant the need to play two spinners. Therefore, should Nathan not be able to play at any stage, we wanted to have the best specialist spinner available to us and based on current red-ball form Jon warrants that spot."
Uncapped paceman Richardson will travel to South Africa along with Mitchell Starc, Josh Hazlewood and Pat Cummins.
The 21-year-old made his one-day international debut against England at the Gabba last week, finishing with figures of 2-57.
"Jhye is a talented right-armer that bowls with very good pace through the air. He impressed in his first one-day international and has bowled well in the Sheffield Shield this season. He is an exciting young prospect who will benefit immensely from his time with this squad," Hohns added.
Meanwhile, David Warner will captain Australia in their Twenty20 international tri-series against New Zealand and England, starting at the SCG on February 3.
Warner will remain in Australia while his Test team-mates fly out to South Africa on February 15, with regular skipper Steve Smith rested for the T20 series.
Hobart Hurricanes star D'Arcy Short is set to make his T20 bow, while big-hitting batsman Glenn Maxwell - overlooked for the Tests and ODIs against England - is in the squad.
"Steve has had a very big summer and will benefit from a short break both physically and mentally, before he leaves for South Africa," Hohns said.
"David is a very capable leader and has captained in Steve's absence before and done a fine job. We wanted to ensure the T20 side had key leadership throughout this series and we know the team is in good hands with him at the helm."
Australia Test squad: Steve Smith (c), David Warner, Cameron Bancroft, Usman Khawaja, Peter Handscomb, Shaun Marsh, Mitchell Marsh, Tim Paine, Mitchell Starc, Josh Hazlewood, Pat Cummins, Nathan Lyon, Jackson Bird, Jon Holland, Jhye Richardson.
T20 squad: David Warner (c), Aaron Finch, Ashton Agar, Alex Carey, Ben Swarshuis, Travis Head, Chris Lynn, Glenn Maxwell, Kane Richardson, D'Arcy Short, Billy Stanlake, Marcus Stoinis, Andrew Tye, Adam Zampa.