The LA Chargers have a lot of players in the last year of their contracts in 2020. The most notable players that the Chargers are going to have to renegotiate after this season are Joey Bosa, Hunter Henry, Desmond King, Keenan Allen, Melvin Ingram and maybe even Tyrod Taylor.
The good thing is that the Chargers have very little on the books for the 2021 season and the cap is projected to rise (although with the current financial status of sports leagues that could change), so they should have enough to afford a few big extensions.