Aminu, 24, averaged 5.6 points and 4.6 rebounds in 74 games for the Dallas Mavericks last season.
Blazers general manager Neil Olshey was GM of the Los Angeles Clippers when they made Aminu the eighth overall pick of the 2010 NBA draft. Aminu also played with New Orleans for three seasons.
After the Blazers traded Nicolas Batum to the Charlotte Hornets before last week's NBA draft, Aminu gives them one of the most coveted small forwards on the free-agent market. Olshey is trying to maintain flexibility with his roster with roads that could include All-Star forward LaMarcus Aldridge, or not include him, based on Aldridge's decision in free agency.
The Trail Blazers can't officially sign Aminu until July 9 when the NBA's free-agent moratorium ends.
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