What happened: Mike Pettine departed Minnesota last January in a move announced as a retirement. He later said he was unsure it would be permanent, with ESPN reporting linking the exit to differences with Brian Flores.

Why it matters: The background explains Dallas's pursuit of veteran defensive help during a losing start. Minnesota kept Flores in charge of its defense after the January change. The episode remains relevant to how both staffs are evaluated this fall.

What to watch: Watch how Dallas uses Pettine as a senior assistant over the next stretch.