Johnson was a non-participant in practice Wednesday due to a back injury.
This is the first word of Johnson dealing with an injury, though he may have picked it up in Sunday's win over New Orleans. The veteran running back has had minimal usage on offense with just four snaps so far this season, though he's a regular contributor on special teams. Should Johnson be sidelined for Week 8 against Baltimore on Sunday, Travis Homer would likely work as Chicago's No. 3 RB behind D'Andre Swift (groin) and Kyle Monangai.