The Detroit Lions are likely to undergo a lot of change this offseason. Longtime offensive coordinator Ben Johnson has already left to become the head coach of the Chicago Bears. Defensive coordinator Aaron Glenn is a top candidate for the jobs with the New York Jets and New Orleans Saints. Even offensive line coach Hank Fraley is a candidate for the offensive coordinator job with the Seattle Seahawks.
There could be a ton of turnover, even with head coach Dan Campbell remaining in place at the top. But Campbell doesn't foresee the Lions falling out of contention for several reasons.
"That core group is still intact and some of these guys are now -- we've signed some back, some are up on contracts and that'll be ongoing," Campbell said, via The Detroit Free Press. "But yeah, we absolutely do (have a window to contend still). And I think the most important thing is ... you've got your culture, you've got your identity and you've got players that fit into that, and we've got that. We've got players in every pivotal position you can ask for to have success. And those guys are made the right way, so absolutely, our window is open."

Detroit has indeed signed many of its core players to long-term deals. Jared Goff, Amon-Ra St. Brown and Penei Sewell all signed monster contract extensions. Aidan Hutchinson seems likely to sign one this offseason. David Montgomery got extended. Taylor Decker, Frank Ragnow and Graham Glasgow are all under contract for at least the next two seasons. Jahmyr Gibbs, Jameson Williams, Terrion Arnold, Brian Branch, Sam LaPorta, Jack Campbell, Kerby Joseph and more are still on their rookie contracts.
That's the core of the team moving forward, and it should help keep the Lions in contention, no matter how many assistant coaches they lose this offseason. It will, of course, be important to replace those coaches, retain some free agents and continue to do well in the draft, but Campbell is right that the foundation remains in place.