Free also played in the United States Basketball League (USBL) for the Miami Tropics after being waived by the Philadelphia 76ers in March 1987. He was USBL Man of The Year in 1987 and the Miami Tropics won the championship. His USBL stint took place the summer before Free went to the Houston Rockets for the 1987–88 season, which was his last NBA season. For Free, the highlight of that season was November 12, 1987, when he scored 38 points against the Sacramento Kings at ARCO Arena and brought the Rockets back to win the game.