Whether it's a marquee QB or an interior defensive lineman, no team can afford to lose its most valuable player.

So, who steps in if the unfathomable happens? Our NFL Nation reporters and Scouts Inc.'s Steve Muench and Kevin Weidl have teamed up to identify each team's most important player and which player in the 2014 draft each team can target to groom as a potential replacement -- MVP insurance. For some teams, their future stars may be slightly younger than others as draft-eligible non-seniors are denoted with an asterisk.

While he had more drops than any other season in his career, there is little doubt Calvin Johnson is the most valuable player on the Detroit Lions. The evidence was especially there this season, when the team couldn’t do much on offense in the games he was out or was limited.

A rising MVP, though, would be on defense, where linebacker DeAndre Levy has turned into an emerging playmaker.

The good thing for Detroit is both of these players are locked up for at least a little while. Johnson is under contract until 2019 and Levy until 2015.

But Detroit also knows it needs to use this year’s draft to build depth behind Johnson and Levy and, in Johnson’s case, to find someone to complement him on the opposite side.

In doing so, that will help open up defenses more, potentially meaning less double teams for Johnson in future seasons. It also gives quarterback Matthew Stafford another target on offense, something that became an obvious need once Johnson went down.

In Levy’s case, he’s still young at 26 years old and is coming off a season where he had 118 tackles and intercepted six passes -- second-most in the NFL. And while the Lions have positions of bigger need, notably in the secondary and at wide receiver, linebacker is a spot Detroit could end up addressing somewhat early in the draft.