A source told NFL.com's Ian Rapoport that Spikes has been informed of his release, which the team later confirmed Thursday morning.
Spikes commented on his release via Twitter on Thursday morning: "Thank you to the @chargers, Spanos family & fans for the opportunity to represent the organization. I look forward to this upcoming season."
Spikes plans to play another season, the source told Rapoport, and he stands a good chance at finding a role as a reserve inside linebacker. He wound up starting all 32 games for the Chargers over the last two seasons, which was not part of the team's original plan for him. Spikes was set to make $3 million in 2013.
"Takeo is a true professional and a class act," Chargers general manager Tom Telesco said in a statement. "We're grateful for his many contributions to the Chargers organization, both on and off the field, and wish him nothing but the best in the future."
The two-time Pro Bowl linebacker, who also has played with the Cincinnati Bengals, Buffalo Bills, Philadelphia Eagles and San Francisco 49ers since entering the NFL in 1998, has yet to play in a postseason game. Spikes holds the distinction of playing in the most NFL games (219) without a playoff appearance.
Spikes will be a guest on "NFL AM" on Monday; he's done a lot of media work over the years and figures to transition to the dark side after his playing career is over. He just doesn't want it to end yet.Follow Gregg Rosenthal on Twitter @greggrosenthal.