The San Diego Chargers placed defensive end Luis Castillo on injured reserve Wendesday and signed linebacker Nate Triplett to a contract.
Castillo suffered a broken left leg during the season opener on Sept. 11. The team kept the 28-year-old on the roster with the hope that he'd heal toward the end of the campaign.
The 28th overall pick of the 2005 draft, Castillo has collected 211 tackles, 19.5 sacks and two interceptions in seven seasons with the Chargers.
After spending seven weeks on San Diego's practice squad last year, Triplett played in three games with the Indianapolis Colts this season.