The 7-foot center has opted out of the final year of the four-year rookie contract he signed with the Bucks after they made him the No.1 pick of the NBA Draft in 2005, in an effort to negotiate a more lucrative deal that could be worth $80 million.
But until he signs a new deal, he does not have insurance against injury.
"He's not playing with us until he signs his contract," Australia's national team coach Brian Goorjian told the Melbourne Herald Sun newspaper.
Still, Goorjian and Bogut both told the newspaper they expect Bogut will sign a deal in time. He cannot do so until July 1, but any significant delay could keep him from the Boomers' final pre-Olympic training camp starting July 16 in Australia.
For the moment, Bogut is sitting out a two-game series with New Zealand, and he won't play on an upcoming tour of Europe. He already missed a three-game exhibition series against Iran. That hasn't stopped him from saying that a top-four finish is realistic for Australia.
"We have to definitely aim for a top-four finish," he told the Herald Sun, "but doing that in international basketball is something else."