Next season, Johnson's expiring contract can be utilized if the Suns chase after any trades where large salaries are swapped.
Johnson, who is averaging 10.8 points, 2.5 assists and 2.8 rebounds in 25.5 minutes per game this season, has one left year on his contract, assuming he opts in for $19.3 million next season.
The 26-year-old Johnson is in his fifth National Basketball Association season.
He is owed $19 million this year with a player-option for the following season.
As for Ellington, the 3-point specialist had fallen out of the team's rotation, ultimately sacrificed for luxury-tax relief.
Anderson has appeared in just three games since November and is unlikely to be any more involved in Miami.
Ellington will be an unrestricted free agent after this season.
The Phoenix Suns finally added a point guard. At the time it was a necessary evil for the Heat to match the four-year $50 million restricted offer sheet the Brooklyn Nets gave to Johnson in the light of Wade's bitter departure to the Chicago Bulls.
Anderson, an 11-year National Basketball Association veteran, has appeared in 637 career games (289 starts) averaging 12.5 points, 5.3 rebounds and 26.2 minutes while shooting 42.2 percent from the field, 38 percent from three-point range and 85.4 percent from the foul line.