A fourth-year veteran, Cooper is viewed as key to the Chargers' future, and was set to play in 2006 under the one-year qualifying offer he signed earlier in the spring as a restricted free agent. That deal was worth $1.55 million. Without the new contract, Cooper would have been eligible for unrestricted free agency next spring and, even though he has started only four games, would have generated interest from other teams.
"I wanted to be here and the organization wanted me to be here, so I'm just glad that it worked out the way it did," Cooper said. "I know the defense, and now that I've been in [coordinator] Wade Phillips' system for three years, I can go out and try to do my job to the best of my ability. I'm 27 years old, and would love to never move again."
The signing of Cooper is just the latest move by general manager A.J. Smith to lock up a talented young player with a long contract. The Chargers earlier signed wide receiver Eric Parker, center Nick Hardwick and cornerback Quentin Jammer to extensions.
Completing a deal with Cooper was crucial for San Diego, not just because the Chargers consider him to be an ascending player and physical defender, but also because of the composition of the team's inside linebacker depth chart. All three other inside linebackers on the roster are in the final seasons of their contracts. Veteran Randall Godfrey is expected to retire after this season and the other veteran starter, Donnie Edwards, is on the trade block. The Chargers would like to extend the contract of their other young standout inside 'backer, Matt Wilhelm.
"Stephen is one of our young, fast-rising players," Smith said in a statement. "He's a hard worker, he's tough and he is physical."
Originally signed by the Chargers as an undrafted college free agent in 2003, Cooper has never missed a game in three seasons. In 48 appearances, the former University of Maine standout has started four times, and he has 97 tackles, 2½ sacks, one interception, two passes defensed and one fumble recovery.
Len Pasquarelli is a senior NFL writer for ESPN.com. To check out Len's chat archive, click here.