Ron Rivera used to play for the Bears as a linebacker .
The Panthers joined the 1984 49ers , 1985 Bears ( which head coach Ron Rivera was a linebacker on that team ) , 1998 Vikings , 2004 Steelers , 2007 Patriots ( who were a perfect 16–0 in the regular season ) , and the 2011 Packers as the only teams to accomplish this .
2015 Carolina Panthers season