Johnson, who suffered an unspecified injury during Sunday's win over the Jaguars, isn't slated to practice Wednesday, Aaron Wilson of Sportstalk 790 Houston reports.
The injury explains why Johnson logged just six carries Week 15, despite starting in a game that Houston controlled throughout. Rex Burkhead led the way with 16 rushing attempts and would be in line to lead the backfield again if Johnson ends up sitting out Sunday against the Chargers.