There are 5 positions that stand out as needing major work.
Some will be easier to fill through the draft, but they need depth either way.
However, where is the fun in speculation if you have to factor that into the situation.

Note: Most of this info is fromSpotrac, so yell at them if anything is wrong.
Chark: He has 4.3 speed and ranked 6th on the year in big play percentage this season.
He’s going to get close to $10 mil AAV this offseason.

He finished the year 4th in big play % and should cost around $1.25 mil AAV.
Parham is injured a lot and both him and McKitty just aren’t good blockers.
They need someone who can pop a big play but also someone who can block.
Luckily, there are some cheap options in free agency and also a loaded draft class.
Spotrac has him looking at about $750k AAV which is very affordable.
UNREALISTIC OPTION- Dalton Schutlz: He’s a really good receiver, but not a particularly great blocker.
The Chargers won’t be able to afford his $10 mil price tag regardless.
MAYBE OPTION- Chris Manhertz: He’s not a receiver, but god damn can this guy block.
He’s essentially an extra offensive lineman which the Chargers could use desperately in the run game.
He can catch but more importantly, he can block like a lineman.
LG
Matt Feiler was a great plug-in but he is coming off his worst year as a pro.
They need someone that can help make that left side unbeatable.
At around $1 mil AAV, he would be a solid replacement for Feiler.
UNREALISTIC OPTION- Isaac Seumalo: This is a large dude that knows how to move people.
He was fantastic in the passing game and very solid in the run game.
He finished the year top-15 in PFF in that category.
Looks like he will get around $2 mil AAV which isn’t totally out of reach.
DRAFT OPTION- I initially had Cooper Beebe here before realizing he didn’t declare.
I’ll sub inEkiyorsince he seems within reach with the chargers pick set.
They need better pressure off the edge which SHOULD come organically with a full season of Mack + Bosa.
CHEAP OPTION- Morgan Fox: Foxy had a fantastic year with the chargers and deserves to be re-signed.
MAYBE OPTION- Ogbonnia Okoronkwo: The Texans were ass but Okoronkwo was a bright spot.
He had a pass rush grade of 81.9 which makes him an easy target for this team.
The question will be if he lasts that long.
Honestly, I’ll take anyone off that Georgia defense.
ILB
Drue Tranquill earned himself a new contract but he needs a running mate.
Kenneth Murray hasn’t lived up to his first round hype and both sides clearly need to move on.
CHEAP OPTION- Alex Anzalone: He isn’t particularly incredible at anything, but he is a tackle machine.
Really solid vs the run and excellent in coverage.
MAYBE OPTION- Tremaine Edmunds: Like David, he is excellent in coverage and a better pass rusher.
However, he struggles vs the run which is what they really need.
He’s only 25 and he looks like he will be getting a little over $3 AAV.
He should be available day 2.