Roberts, 30, played 30 games with Charlotte last season and then was traded to the Heat. He never played for the Heat before being traded to the Portland Trail Blazers. He averaged 4.0 points in 51 games.
Roberts debuted in 2012 with New Orleans. In four NBA seasons, he has averaged 7.0 points per game. He has shot 91.5 percent at the free-throw line in his career.