Dallas Cowboys defensive coordinator Mike Zimmer has held several notable positions around the NFL dating back to 1994 with the Dallas Cowboys, but he was only hired as a head coach once. That was with the Minnesota Vikings from 2014 to 2021. For the majority of that time, he worked with GM Rick Spielman. The beginning of the end of both of their tenures seems to have involved current Pittsburgh Steelers backup QB Justin Fields.
Fields was a highly sought-after prospect in the 2021 NFL Draft and Spielman, although he had QB Kirk Cousins under contract, was a big fan of Fields.