It comes less than a month after John McEnroe criticized the current state of the doubles game, saying the standard of players is poor and the money would be better spent on struggling singles players.
On Sunday, the 41-year-old Rafter said he would come out of more than a decade of retirement to play with Hewitt, although how far they go in the doubles draw might depend on how long Hewitt stays active in singles.
The 32-year-old Hewitt plays his first-round singles match against No. 24 Andreas Seppi on Tuesday.
Rafter hasn't played since Australia's Davis Cup final loss to France in Melbourne in 2001. He and Hewitt, both two-time Grand Slam singles champions, were drawn to play American Eric Butorac and Raven Klaasen of South Africa in the first round of the doubles.
Hewitt, when asked if there was a serious side to the doubles pairing, responded: "Not really. Just a bit of fun."
"I think he still thinks he's got it in him, so... Hope I don't have to carry him too much," Hewitt added, smiling. "He's hitting the ball well enough. Beat (Goran) Ivanisevic and (Tim) Henman and those guys over in the seniors tour."
Rafter appeared to play down any long-range plans for the twosome.
"Listen, nothing is happening just yet," Rafter said. "We're in the draw, but it will all depend on how he goes. It's really important for him to play great singles. That's what it's all about.
"But I'll have fun. I'm playing with one of the best players in the competition. Figure it's like eating chocolate or having broccoli, sort of equal it out."
McEnroe, despite having won 71 doubles titles, many of them with regular partner Peter Fleming, in addition to his 77 singles titles, was scathing in his criticism of doubles during a gathering in London during a Masters tournament in December.
"If you cut out doubles and gave that money to singles players ranked between 200 and 1,000, maybe that would do something for the game," McEnroe was quoted as saying. "Most doubles players, I hate to say, are the slow guys who were not quick enough to play singles. Why we are even playing doubles at this point is a mystery to me."
The winning men's and women's doubles pairs at the Australian Open will each receive almost a half-million dollars.
Rafter, who could split $12,000 with Hewitt even if they lose in the first round, was asked whether he had any concerns about passing a doping test in his comeback.
"If there's a law, mate, against eating too much chocolate, I'm in trouble," Rafter said.