However, the Chargers have not gotten enough bang for their buck.
Merriman struggled through an injury-plagued, four-sack season in 2009. The team hopes he will be better this season now two years removed from reconstructive knee surgery, but it's been three years since he was a difference-maker. Regardless of his showing this season, he will likely play out the one-year deal he signed as a restricted free agent and move onto another team next year, assuming he's not traded first.
English was drafted to be Merriman's heir apparent, but posted just two sacks as a rookie. He earned good reviews for his progress this offseason, but he's still without a sack this preseason and needs to prove he can get it done on game days.
Phillips is the most productive member of the trio, getting at least seven sacks in each of the last five years and setting a franchise record with seven forced fumbles in 2009. The drawback is that he's a hothead on and off the field, as evidenced by the 15-yard penalty he drew for a head-butt in last season's playoff loss, as well as the two civil suits he faces for allegedly throwing punches.
LB Antwan Applewhite
At inside linebacker, the team is led by the polarizing Stephen Cooper. The eighth-year linebacker has led the team in tackles for three straights seasons, yet is often criticized for making too many tackles downfield and for not making enough game-changing plays. Still, there is a reason the coaches had him on the field for more snaps than any other player last season (940) -- he gets the job done.
The Chargers wanted to spell Cooper more this season, hoping third-round pick Donald Butler could take some of his snaps before eventually taking over for the senior member of the unit. However, Butler tore his ACL during offseason workouts and will miss his rookie campaign.
Starting next to Cooper will be Kevin Burnett, the team's big free-agent acquisition from a year ago. Burnett had 66 tackles and 2.5 sacks in his first year in San Diego, numbers that were muted by a neck injury that cost him five games. The Chargers hope that a healthy and better-acclimated Burnett can make a bigger impact in '10.
With Tim Dobbins now in Miami, the top backup job is all Brandon Siler. A seventh-round pick in 2007, Siler quickly emerged as an elite special-teams player and force in short-yardage situations. He is now focused on becoming a more complete player and figures to split time with Burnett.
The injury to Butler and the trade of Dobbins opens the door for one more inside linebacker to make the final roster. James Holt, who made the team as an undrafted free agent last season, and fellow second-year player Darry Beckwith are the top candidates. Holt is an impact player on special teams, while Beckwith is averaging six tackles per game so far this preseason.
Undrafted rookies Mike Nixon (Arizona State) and Kion Wilson (South Florida) are likely auditioning for other teams, although Nixon obtained praise from the coaching staff despite joining the team after the first wave of rookies.
Can Antwan Applewhite crack the starting lineup? Discuss in the message boards.
Michael Lombardo is a member of the Pro Football Writers of America and a long-time contributor to the Scout.com network. His analysis has been published by the NFL Network, Fox Sports and MySpace Sports. He has followed the Chargers for more than 15 years and covered the team since 2003. You can see more of his updates by following him on twitter.