The 28-year-old, who has 46 caps for the Wallabies and scored a try in the 1999 World Cup final win over France, was on the brink of retirement after a series of knee injuries threatened to ruin his promising career.
But after multiple knee reconstructions, he put in a full season with the Queensland Reds in 2005 and was named in Australia's initial 45-man squad for their recent tour of Europe.
While he failed to make the final squad, Tune believes he still has a chance of featuring in the next World Cup, which is being held in France in less than two years' time.
"It is premature but it's still a goal," he said.
"I think if you're a professional rugby player, that should be everyone's goal.
"It's our Olympics. And if you rate yourself at all as a rugby player, then you want to be competing against the world's best in the biggest tournament rugby has to offer - and that's the World Cup."
Although playing for Australia again is his long-term aim, Tune admits featuring regularly for his provincial side this season is his first priority.
"It depends on how I go achieving my goals with Queensland," he added.
"I guess it's to play every Super 14 game and to play well.
"I'm quietly confident that if I can do that and play up to the standard I can, I can win back a Wallaby jersey.
"Whether or not that will be in the starting team or on the bench I don't know, I'm not thinking that far ahead. I like to think I can force my way back into the squad."