Since CBS and FOX each get one of the daytime games, there was always an AFC team slated as one of the opponents for whichever game was scheduled to air on CBS. For years, CBS had exclusively been affiliated with games featuring at least one AFC team, with FOX having the same arrangement for the NFC.
That changed entering the 2014 season, as the league began “cross flexing” games between the two networks after Week 5, allowing CBS to air two NFC games and vice versa to balance out the television schedule.