4. J.C. Jackson
J.C. Jackson was the biggest signing that the LA Chargers made this offseason and it is undeniable that he is extremely important to the team's success next season. Is he the most important player on the Chargers? No he is not. But outside of Derwin James, Jackson is the most important player on the defensive side of the ball for the Chargers.
The run defense got most of the blame for the defense's struggles last season and rightfully so. LA had one of the worst run defenses in the entire league and this run defense is what allowed teams to have short third-down attempts, which in turn, led to a horrible third-down stop rate for the Bolts.
That being said, the secondary was not very good, either. Michael Divas took a step back, Asante Samuel Jr. was hurt for a lot of the season and Chris Harris Jr. simply was not good. Tevaughn Campbell played a big number of snaps and he was exposed nearly every single game.
Replacing what the Chargers got last season in the secondary with what they will get this year, led by Jackson, is such a big deal. Jackson is going to have a domino effect on the secondary that will make his teammates better even when he is not the one making the plays on the football.
And when he is the one making the plays on the football he is going to do a great job. The Chargers have struggled with takeaways for awhile now and in Jackson they signed one of the best interception artists in the entire league. That is important.
But again, if we are going back to the thought process of removing a player from the roster and seeing what the record would be, Jackson has to be ranked below the other three on this list. A Chargers team without Herbert, James, or Slater is still worse than a Chargers team without Jackson.