The team statement did not name a successor. The San Diego Union-Tribune said linebackers coach John Pagano was considered by its sources to be a likely candidate for the position.
Manusky was the first casualty in an anticipated overhaul of the Chargers coaching staff following the somewhat surprising decision to keep Head Coach Norv Turner on the job after two disappointing seasons in which San Diego failed to make the playoffs.
Manusky, who had been the 49ers defensive coordinator, stepped into some big shoes this season when he was hired to replace Ron Rivera. Rivera took the head coaching job in Carolina after leading the Chargers defense to the No. 1 ranking in the NFL in both pass defense and total defense in 2010.
This season the Chargers slipped to 16th in defense and had the league's worst record in third-down defense. The Chargers gave up more than 30 points in three games and allowed Oakland's Carson Palmer to rack up 716 yards and four touchdowns in two games.