Key is dealing with a minor hamstring issue, Jim Wyatt of the Titans' official site reports.
Per Wyatt, the team hopes that Key will be back in action next week. Key, who coach Brian Callahan said has solidified himself as a three-down linebacker with a solid showing in camp, reportedly recently won his appeal to overturn a six-game suspension under the NFL's policy against performance-enhancing substances, according to The Athletic. Key is projected to man a starting outside linebacker slot for the Titans opposite Harold Landry.