The Rams have avoided a local television blackout each of the first seven home games. Their final three games last year were not sellouts in a 1-15 season.
Sunday's game matches surprise division leaders, with St. Louis ahead in the NFC West and Kansas City atop the AFC West.
The teams have regularly competed for the Governor's Cup in the preseason, meeting 11 times since the Rams moved to the Midwest in 1995, but this will be just their fifth regular-season game.
Copyright 2010 by The Associated Press