Behanan, who would be a junior this season, was suspended indefinitely for a violation of university policy. Louisville Coach Rick Pitino didn't go into detail about the specific violation.
"We set up a situation for him to come back and he already violated it," Pitino said. "It's multiple things. Don't ask what it is. We're not going to tell you."
The coach said the earliest Behanan could rejoin the team would be mid-December.
Behanan averaged 9.7 points and 6.5 rebounds a game last season, which ended with Louisville beating Michigan in the NCAA Tournament final. Behanan scored 15 points and had 12 rebounds in the title game.
Louisville, 35-5 last season, was No. 3 in the USA Today coaches' pre-season poll, which was released Thursday.