The 27-year-old Kupp, who is the team's leading receiver, has caught 92 passes for 974 yards and three touchdowns in his fourth NFL season. He also led L.A. in receiving in 2019.
The list was established for players who test positive for COVID-19 or who are determined to have been in close contact with someone who has tested positive. Teams aren't permitted to disclose under which category a player falls.
Either way, Kupp will miss his team's game on Sunday. Returning to the field following close contact with an infected person requires five straight days of negative tests for the player, who can then return to the team on the sixth day after contact. Infected players may not return to play until at least 10 days after a positive test.
Robert Woods, Josh Reynolds and Van Jefferson figure to be the Rams' top three wideouts in Kupp's absence.
The Week 17 status of running back Cam Akers, who missed last Sunday's 20-9 loss to the Seattle Seahawks with a high ankle sprain, is unknown at this time.
The winner of the Rams vs. Cardinals game will make the playoffs. The loser will still make the playoffs but only if the Chicago Bears lose to the Green Bay Packers.
The Rams-Cardinals kickoff will take place on Sunday at 4:25 p.m. ET in Los Angeles' SoFi Stadium.