The move allows the Heat to save a little bit of money by getting off of Johnson's $19.3 million next season while Anderson is guaranteed $15 million next season. The Suns are expected to waive Ellington who will then be eligible to sign with a contending team. He is averaging 3.7 points and 18.5 minutes.
Phoenix will also receive guard Wayne Ellington, according to The Athletic's Shams Charania.
Johnson, 26, joined the Heat as an undrafted free agent during the 2014-15 season, playing well enough to earn a four-year, $50 million offer sheet from the during the 2016 offseason as a restricted free agent.
Phoenix will send Ryan Anderson to Miami in return. Johnson had been positioned to take a more Heat-friendly version of his contract, a factor that had not sat well with the Heat moving forward.
Ellington will be an unrestricted free agent after this season. Last season he was one of Miami's most important rotation players and most effective perimeter threat.
Ellington, a career 38 percent shooter from deep, had appeared in only 25 games this season for the Heat as the team was unable to find minutes for him. He also has played for the Rockets, Pelicans, Magic and Nets during his career, averaging 12.5 points and 5.3 rebounds. It will be tricky to get under with the need to fill roster spots, but Heat general manager Andy Elisburg is one of the best executives in the National Basketball Association when it comes to understanding the salary cap.