Armour-Davis (hamstring) was placed on injured reserve Saturday, Jonas Shaffer of TheBaltimoreBanner.com reports.
Armour-Davis sustained a hamstring injury during the Ravens' Week 3 win over the Cowboys, and he had already been ruled out for Sunday's contest against the Bills before moving to IR on Saturday. With the third-year corner set to miss at least Baltimore's next four games, expect T.J. Tampa to see increased work in the Ravens' secondary.