Smith retired for a second time following Australia's 1-2 series loss to the touring Lions in 2013.
Cheika said he had no idea if he'd be able to temp the champion flanker to make a second international comeback, but said the 34-year-old was "obviously" an attractive proposition.
"George played for me at Stade Francais," Cheika said. "He came on one of his little junkets out of Japan and came over and had had a little of life in France and I can tell you he was an awesome player to coach."
Cheika said it was too early to say if any of the three overseas-based options would need to return for the Rugby Championship or simply slot into his 31-man World Cup squad for this year's global showpiece in Britain.
Meanwhile, former England coach Clive Woodward said England should follow Australia's lead and scrap their "old-fashioned" policy of refusing to select overseas-based players.
"Stuart Lancaster [England coach] must be free to pick his best players, no matter where they ply their trade," Woodward wrote in his column for Britain's Daily Mail.
"It's wrong to say England are best served by players at English clubs."
Woodward cited the in-form Toulon pair of Steffon Armitage, the reigning European Player of the Year, and fullback Nick Abendanon as two players who ought to be considered for England's World Cup squad.
"When it comes to a home World Cup, you don't want to be left talking about 'what ifs'," he said.
- AAP