Joko Widodo, who is this year's chair of the bloc of major economies, said Putin during a phone conversation last week had not ruled out attending the summit in Bali, and would join if possible.
"But if not ... maybe he'll ask to do it virtually," Jokowi, as the Indonesian president is popularly known, told reporters during a visit to Bali. He did not elaborate.
The Financial Times newspaper earlier quoted Jokowi as saying that his conversation with Putin had left him with a "strong impression" he would not attend.
The Bali meeting is expected to be dominated by tensions over Russia's invasion of Ukraine, which Moscow calls a "special operation".
The Indonesian foreign ministry and presidential palace did not immediately respond to requests from Reuters for comment.
As G20 host, Indonesia has resisted pressure from Western countries and Ukraine to disinvite Putin from the leaders summit and expel Russia from the group, saying it does not have the authority to do so without consensus among members.
Jokowi in an interview with the Financial Times said Russia was welcome at the summit, which he feared would be overshadowed by a "very worrying" rise in international tensions.
"The G20 is not meant to be a political forum. It's meant to be about economics and development," he was quoted as saying.
Indonesia has also invited Ukrainian President Volodymyr Zelenskiy, who has said he would not take part if Putin does.
Several other world leaders, including U.S. President Joe Biden and Chinese President Xi Jinping, are expected to attend.