The Heat announced Saturday all three players have been waived, bringing their roster to a total of 17 players.
McCree was the longest-tenured player of the trio, though he had been with the team less than one month after signing on Sept. 18. He scored six points in two preseason games.
Liggins and Mitchell were with the Heat for less than one week. Liggins played nearly 27 minutes during Friday's game against the Philadelphia 76ers, and Mitchell didn't appear in a game for the Heat.
Liggins has the most NBA experience under his belt. The 29-year-old has bounced around to the Orlando Magic, Oklahoma City Thunder, Heat, Cleveland Cavaliers and Dallas Mavericks in four NBA seasons. He also spent time playing in Germany, Russia and the NBA Developmental League from 2014-16.
Mitchell was a second-round draft pick by the Detroit Pistons in 2013 and appeared in 21 games as a rookie.