Christian Lealiifano has been named in Australia's squad for the first time since being diagnosed with blood cancer leukaemia in August 2016.
The Brumbies fly-half, who is now in remission having been clear of any signs of the disease for two years, last played for Australia in June 2016.
The 31-year-old is in the 34-man squad for the Wallabies' Rugby Championship opener against South Africa on 20 July.
"He deserves to be there," said Australia coach Michael Cheika.
"If you take out the other things that he's achieved, he's been playing good rugby.
"I'm not the expert to speak on what Christian has been through, only he knows that and his family. What you can't deny is his form in Super Rugby."
Lealiifano, who captains Canberra-based team Brumbies, has made 19 appearances for Australia. His inclusion means there is no room for Melbourne Rebels fly-half Quade Cooper, who made the last of his 70 international appearances two years ago.
Scrum-half Nick Phipps, who has 71 international caps and flanker Ned Hanigan have also missed out.
Joe Powell and Nic White have been chosen as understudies to regular scrum-half Will Genia, with Toomua and Lealiifano, who has also had a successful stint with Ulster, the likely backups for regular fly-half Foley.
Australia host Argentina on 27 July and New Zealand on 10 August in the annual four-team Rugby Championship, which is being halved from six to three games this year because the World Cup starts in September.
Australia open their World Cup account against Fiji on 21 September.