Key (back) did not practice Wednesday, Jim Wyatt of the Titans' official site reports.
Key finished this past Sunday's 27-17 loss to the Chargers with two solo tackles, but he appears to have picked up a back injury in the process. He'll have two more chances this week to practice and avoid an injury designation heading into Sunday's game against the Vikings. In the five regular-season games since the Titans' Week 5 bye, Key has logged 13 tackles (nine solo), including 4.0 sacks, and two forced fumbles.