Players association attorney Michael Weiner says the union will file a grievance claiming the Astros improperly terminated the deal.
Weiner says Chacon is owed the remaining nearly $984,000 of his two million dollar salary this year.
The 30-year-old pitcher was suspended after shoving Wade to the floor before the Astros played the Texas Rangers last Wednesday.
Wade says he asked Chacon to go into manager Cecil Cooper's office for a meeting. Chacon refused -- and the confrontation ensued.
Chacon's agent didn't immediately comment.
Chacon was 2-3 with a 5.04 ERA in 15 starts this season.
The Astros say Chacon violated a provision in the uniform player contract that states the player may be terminated if he shall "fail, refuse, or neglect to conform his personal conduct to the standards of good citizenship and good sportsmanship or to keep himself in first-class physical condition or to obey to the club's training rules."