Though he has put his own spin on a lot of the stuff he does with the Vikings, O’Connell still speaks glowingly about his time with the Rams. He referenced how he was actively involved in the preparation on a weekly basis and how that played a role in building his confidence.

As they face off on "Thursday Night Football," here's what to know about the relationship between the two NFL head coaches.

O'Connell has evolved as a play-caller and an offensive planner since he learned many of his methods while he was an assistant to McVay on the Rams staff in Los Angeles.