* O'Connor back after six years in wilderness
* Cancer survivor Lealiifano named starting flyhalf
* Cheika makes five changes to starting side at Lang Park
* (Adds Cheika quotes)
MELBOURNE, July 25 (Reuters) - James O'Connor is poised to play his first test in six years after being named on the Australia bench in a revamped squad for the Rugby Championship clash against Argentina on Saturday.
The former bad boy of Australian rugby, whose last Wallabies contract was torn up in 2013, missed the opening defeat away to South Africa but will hope to push for a World Cup berth in the match against the Pumas at Lang Park.
Coach Michael Cheika said the versatile back deserved his chance in a rejigged side featuring five changes from the team that started the 35-17 defeat at Ellis Park last week.
"He's had a good season overseas," Cheika said of the 29-year-old, who was released by English club Sale to pursue his World Cup dream.
"He's integrated himself well with the players ... He can play many positions so he's handy in that type of slot as a finisher.
"I'm sure he had that very nervous look on his face when the selection came out and he's so excited to play ... I haven't coached him before so it's going to be a great opportunity for me to have a look at him on the field."
Saturday's match will feature another Wallabies return in the form of Christian Lealiifano, who replaces Bernard Foley at starting flyhalf for his first test in three years, capping a brave comeback from a cancer battle.
Veteran scrumhalf Will Genia, set to retire from internationals after the World Cup, replaces Nic White for his last bow at Lang Park where he thrilled home fans for years as a Queensland Red.
Kurtley Beale dislodges Tom Banks at fullback, with winger Dane Haylett-Petty dropped in favour of Marika Koroibete after bombing a try chance against the Springboks.
Utility back Beale, who has played most of his rugby at inside centre since the 2015 World Cup, came off the bench against the Springboks and helped spark the Wallabies' attack despite their convincing defeat.
"He's been training really hard and he's fit as I've seen him for a long time and that's always a good sign with KB," Cheika said of the 30-year-old.
"In saying that I thought Banks was good for us as well.
"It's been probably a while since (Beale) started a test at fullback so it's going to be a chance for him."
Beale last started a test at fullback against Scotland at the end of the 2017 season with his opportunities to play in the number 15 shirt blocked for several years by Israel Folau, who was sacked earlier this year.
Prop Scott Sio replaces James Slipper in the fifth change to the starting side as the Wallabies seek to fix their scrum after being schooled by the South Africa pack in Johannesburg.
The midfield is under scrutiny after Tevita Kuridrani had a quiet match against the Springboks but Cheika said the centre deserved at least one more shot outside fellow Fiji-born back Samu Kerevi.
"They're good friends, they look good together. I want to give that pairing a chance to flourish," he said.
Australia team: 15-Kurtley Beale, 14-Reece Hodge, 13-Tevita Kuridrani, 12-Samu Kerevi, 11-Marika Koroibete, 10-Christian Lealiifano, 9-Will Genia, 8-Isi Naisarani, 7-Michael Hooper (captain), 6-Lukhan Salakaia-Loto, 5-Rory Arnold, 4-Izack Rodda, 3-Sekope Kepu, 2-Folau Fainga'a, 1-Scott Sio
Replacements: 16-Tolu Latu, 17-James Slipper, 18-Taniela Tupou, 19-Rob Simmons, 20-Luke Jones, 21-Nic White, 22-Matt To'omua, 23-James O'Connor (Reporting by Ian Ransom; Editing by Nick Mulvenney)