Caldwell did not rule out sitting Johnson for a week at some point this season if they thought it would help his long-term health.
Here are some more injuries we're following on this Week 5 Friday:
3.* *Jets coach Rex Ryan took the podium Friday with some surprising news: Wide receiver Eric Decker (hamstring) will be a game-time decision after sitting out of practice, and David Nelson (ankle) is listed as questionable after participating in limited fashion, but Ryan expressed optimism about Nelson's status.
9.* *Niners coach Jim Harbaugh said it's still questionable if tight end Vernon Davis (back) or offensive lineman Anthony Davis (knee, ankle) will play Sunday against the Chiefs. Eric Reid (hamstring) is also listed as questionable. Safety Antoine Bethea (ankle), wide receiver Michael Crabtree (foot) and running back Frank Gore (back) are probable.