Leonard’s second 10-day expired on Monday night, meaning the Bucks either had to sign him for the rest of the season or let him enter free agency.
Leonard, 31, is 7-foot-0 and before his recent 10-day deal, last played in the NBA in the 2020-21 season, when appeared in three games with the Heat. He played 51 games with Miami the year before that, averaging career-highs of 6.1 points and 5.1 rebounds.
Earlier this season, he worked out for the Lakers.
Originally drafted by the Trail Blazers with the No. 11 overall pick in 2012, Leonard spent seven seasons in Portland before being sent to the Heat as part of the multi-team Jimmy Butler deal.
He was traded by the Heat to the Thunder for forward Trevor Ariza in March 2021, then immediately waived.