Here is a preview and ranking—based on a not-so-secret recipe combining past performances and future projections—of each defensive unit.
Who: Patrick Willis, Navorro Bowman, Aldon Smith, Ahmad Brooks, Parys Haralson, Larry Grant, Tavares Gooden and Cam Johnson
Why: Two All-Pro tackling machines in the middle and two outstanding athletes on the outside make this the most fearsome linebacking unit in the entire NFL. They do it all: stop the run, pressure the quarterback and effectively drop back in coverage.
Haralson, Grant, and Gooden—a special teams ace—are reliable backups in case of injury, and Johnson, though a rookie, has plenty of upside.
Who: Justin Smith, Ray McDonald, Isaac Sopoaga, Demarcus Dobbs, Ricky Jean Francois and Will Tukuafu
Why: If not for the linebackers, the d-line would easily top the list.
Smith, team captain and defensive end, is equally dominant—58 tackles, 7.5 sacks and three forced fumbles in 2011—as he is underrated. And on the other side, McDonald has quietly developed into a steady contributor.
Sopoaga, though, is "the big engine that could" for the defense. He plugs up the middle and gobbles up multiple blockers, freeing teammates to fly in and make plays.
Depth is a minor issue—only Ricky Jean has recorded a start—but each player is prepared to step in if called upon.
Who: Carlos Rogers, Tarell Brown, Chris Culliver, Perrish Cox, Cory Nelms and Curtis Holcomb
No worries, these guys are up to the task.
Once considered a weak link, the cornerback unit is anything but weak these days. Rogers is fresh off a six-pick season, Brown is a budding star, Culliver a promising youngster and the rest are raw yet talented.
As the 49ers stuff the run—which they do at a league-best rate—and force opponents to become one-dimensional, expect each of these corners to see their fair share of playing time.
Who: Donte Whitner, Dashon Goldson, Trenton Robinson and C.J. Spillman
Why: The starters are solid, no doubt about it. Goldson is a big-hitter with great, albeit risky, ball skills and Whitner is the quarterback of the defense. But what happens if one or the other is unable to go? Who steps in?
As Goldson's contract situation continues to stall, rookie Robinson and special teams standout Spillman continue to receive first team reps. Robinson is the likely replacement at free safety if Goldson leaves.