Armour-Davis (Achilles) is ruled out for Sunday's game against the 49ers, Jim Wyatt of the Titans' official site reports.
Armour-Davis will miss a third straight game while working his way back from an Achilles injury, despite seemingly having made progress at practice in Week 15. His next chance to retake the field will come Week 16 versus the Chiefs. Marcus Harris will stand to continue handling a starting role at cornerback until Armour-Davis retakes the field.