The 29-year-old Queensland Red, who has won 86 caps for the Wallabies, will play his first game since testing positive to cocaine for a second time in May, which saw him banned for two months and fined A$27,500 ($20,400).
When his ban was announced, Slipper revealed that he had been battling depression after suffering a season-ending injury last year and while coping with the illness of a family member.
"James' enthusiasm has really impressed me since we invited him to join," the selection side's coach John Manenti said in a media release on Tuesday.
"He’s keen to be back out there and training hard but also really wants to get his old Wallabies team mates firing ahead of that first Bledisloe. That just shows the character of the bloke."
Slipper will line up with three other capped Wallabies -- Blake Enever, Matt Philip and Richard Hardwick -- in the Tom English-captained side.
The Wallabies will line up without a number of their biggest names, with New South Wales Waratahs players, including Israel Folau and flyhalf Bernard Foley, rested after playing in the loss to the Lions in Johannesburg over the weekend.
The match at Leichhardt Oval will be open and free to the public.
($1 = 1.3504 Australian dollars)
(Reporting by Ian Ransom; Editing by Nick Mulvenney)
