Whittington (back) was placed on injured reserve Tuesday.
This is another blow to the Rams' receiving corps, as Davante Adams (hamstring) is still on IR and Puka Nacua (knee/toe) is slated to miss several weeks. Whittington would have had a chance to carve out a major role in Los Angeles' wideout room, but instead he'll be sidelined until at least Dec. 20. The Rams signed Xavier Smith off San Francisco's practice squad Tuesday to take Whittington's place on the 53-man roster and in the WR corps.