Hamilton averaged 19.3 points, 9.2 rebounds, 2.0 blocks in 37 games earlier this season with the Sioux Falls Skyforce, Miami's NBA Development League affiliate. He also averaged 1.5 assists and 35.8 minutes and shot 49.1 percent.
He recently played in one game with Charlotte after signing a 10-day contract with the Bobcats on March 4.
Hamilton, who played at Iowa State and LSU, was the Heat's second-round pick in 2012.
Liggins, who was signed to two 10-day contracts with Miami, appeared in one game totaling 2 points and 1 rebound in 1:24 minutes.