The move was made after Young openly sulked on the field when quarterback Matthew Stafford didn't throw to him and argued with receivers coach Shawn Jefferson during a Nov. 18 Detroit loss to Green Bay.
The mercurial second-year pro was put on the inactive list for the Lions' last two contests after managing only seven catches for 79 yards over the previous three games.
"When you play a game like football, it's a team sport and players have obligations to the team," Schwartz after the incident. "Titus hasn't done a good job of fulfilling those obligations this week and recently."
Young -- who had also been disciplined earlier for fighting with a teammate -- made 33 catches for 383 yards and four touchdowns over Detroit's first 10 games this season.