The key loss for a team is not always an obvious player.
In the case of the Minnesota Vikings and Green Bay Packers, it might be a coach.
The Bears had more overall losses and additions than anyone in the NFC North, but a few losses stood out more, like Khalil Mack and Akiem Hicks.
A big producer isn't always the key loss when he leaves, especially when they've stop being a producer before they actually depart. Allen Robinson struggled all 2021 with the Bears, and his loss was felt last year.
And sometimes it's not a big name at all who is missed, but a player who has come on strong in his final year and played a vital role on special teams, like Lions linebacker Jalen Reeves-Maybin.