Johnson was elevated from the practice squad by the Rams on Saturday.
The wide receiver was waived by the Rams on Aug. 30 after not making the 53-man roster, but he rejoined the team as a member of the practice squad. Johnson has yet to play in a game this season. The fourth-year pro remains buried behind a slew of healthy wide receivers on the Rams' depth chart in Cooper Kupp, Puka Nacua, Demarcus Robinson, Ben Skowronek and Austin Trammell.