San Diego, CA -- (Sports Network) - The San Diego Chargers have signed defensive end Luis Castillo to a new seven-year contract, locking him up through the 2014 season. Castillo's original rookie contract was set to expire after the 2009 campaign.

"Since his arrival, Luis has played a huge role in the success we've had as a defense," Chargers general manager A.J. Smith said. "He's an ascending player who is committed to getting better. We're thrilled that he'll be a Charger for years to come."

Castillo was selected in the first round (28th overall) by San Diego in the 2005 NFL Draft. He made headlines at the 2005 NFL Combine when he sent a letter to all 32 NFL teams admitting he tested positive for steroids. The Chargers selected him anyway, and the Northwestern product has produced 13 sacks in 36 career games -- 33 starts.