Mitchell reverted to the Lions' practice squad Monday, per the NFL's transaction log.
The third-year pro was elevated to Detroit's active roster ahead of the Week 11 win over the Jaguars to ensure depth at tight end with Sam LaPorta (shoulder) ruled out. Mitchell ended up seeing increased time after Shane Zylstra sustained a neck injury in Sunday's win, playing 24 offensive snaps but failing to record a stat. He could be elevated to the Lions' active roster again before the team's Week 12 matchup against the Colts if LaPorta or Zylstra cannot suit up.