The Fresno State product finished with a team-high 12 special teams tackles in 2013. Ajirotutu, 26, also made some key plays in limited playing time, including a 26-yard touchdown reception that won the game for the Chargers at Kansas City.
Ajirotutu totaled three receptions for 64 yards and a touchdown, and played 70 offensive snaps during the regular season.
Ajirotutu joins Donald Butler, Chad Rinehart, Darrell Stuckey, Reggie Walker and Richard Marshall as free agents retained by the Chargers. San Diego also added running back Donald Brown, quarterback Kellen Clemens, linebacker Kavell Conner, tight end David Johnson and cornerback Brandon Ghee from other teams in free agency.
The addition of Ajirotutu gives the Chargers six receivers currently under contract for the upcoming season -- Keenan Allen, Eddie Royal, Vincent Brown, Malcom Floyd, Dontrelle Inman and Tobais Palmer.
The Chargers now have their top seven special teams tacklers from last season under contract for 2014 with the return of Ajirotutu.