March 15 isn't just the deadline for teams to achieve cap compliance.
It's also the deadline for tendering a contract to restricted and
exclusive rights free agents. If not tendered, they become unrestricted
free agents. The Chargers have 11 players who are in these categories
(OTC lists Fehoko and Gaziano as restricted rather than exclusive rights
free agents, but I don't think that's correct):

https://overthecap.com/free-agency/los-angeles-chargers

Restricted Free Agents (4):

WR Jalen Guyton

T Storm Norton

TE Donald Parham Jr.

OLB/Edge Derrek Tuszka

Exclusive Rights Free Agents (7):

WR Michael Bandy

K Cameron Dicker

NT Breiden Fehoko

DE Joe Gaziano

CB Kemon Hall

DT Forest Merrill

T Foster Sarell

So far the only decision revealed (not officially) is that the Chargers
don't intend to tender Bandy. All these players will be minimum-salary
(for length of service) players if the Chargers retain them.

The Chargers also have 15 unrestricted free agents. The Chargers need
cap room to re-sign some of them:

S Nasir Adderley

CB Bryce Callahan

WR DeAndre Carter

C Will Clapp

DT Christian Covington

QB Chase Daniel

DT Tyeler Davison

DL Morgan Fox

T Trey Pipkins

LB Troy Reeder

TE Richard Rodgers

P JK Scott

QB Easton Stick

LB Drue Tranquill

OLB Kyle Van Noy

--Robin