A franchise still looking to lock down free safety Eric Weddle announced a separate defensive signing on Tuesday.
Chargers general manager Tom Telesco called Liuget a "consummate team player who goes about his work in an unselfish manner," in a release Tuesday. Telesco termed the signing, "another reflection of our commitment to investing in our core players."
The 25-year-old University of Illinois product has logged over 200 tackles in his four-year NFL career, including 18 sacks. He has started in 61 of the Chargers' 64 games during that time span.
Liuget was sixth on the team last year in tackles, with 45, and led the team with 4 1/2 sacks.
In 2014, the Chargers signed then-25-year-old linebacker Donald Butler to a seven-year contract worth more than $51 million.
Last season, the Chargers' defense allowed 21.8 points per game, which was around the middle of the pack in the NFL. The team allowed a ninth-best 338 yards per game.
- Will Green