Spikes may be more accomplished, but Chargers fans know that Butler is the man on the inside. (Photo by Stephen Dunn/Getty Images)
- Run defense: Both Spikes and Butler are explosive players and can use speed and power to get to ball carriers. Butler shows a lot of promise here having forced a couple fumbles last season and generally making a nuisance of himself against opposing blockers.
- Depth: The Chargers have a fair number of bodies at this position now, but whether it's quality depth remains to be seen. The return of Mouton from injury and Williams having a full camp with the team (as opposed to Diggs last year who was signed early in the season) will help create a rotation sorely missed last season. Bird has a little experience under his belt now and it remains to be seen if Gachkar can play anything other than special teams.
- Pass rush: Spikes and Bulter combined for 3 sacks last year. Spikes has never had more than 6 sacks in a season and Butler is not supposed to be a premier pass rusher. Neither is Mouton. Burnett had 6 in 2011, so the unit lost something there.
- Coverage: Spikes had been praised for good coverage in past seasons, but did not show it last year. Butler may have some upside in this area since he has the speed to do it.