San Francisco 49ers: How Important Is Justin Smith to the 49ers Defense?

The San Francisco 49ers were thoroughly hammered by the Seattle Seahawks on Sunday night. The final score was 42-13, and it wasn't even that close.

The 49ers defense was again exposed, as it was last week in New England, when it allowed 28 straight points to Tom Brady and the Patriots. Fortunately, the 49ers were able to score late to win that game, but the failure of the defense was an ominous dark cloud.

This week, the Seattle offense rolled up 35 points against the 49ers defense. The other touchdown came on a return of a blocked field goal.

In the past six quarters, the 49ers defense has allowed 63 points. The only major difference on the defense is that the 49ers have been without standout defensive tackle Justin Smith.

Smith injured his elbow against the Patriots, and the Niners defense has not been the same. If Smith is forced to miss any postseason games or is ineffective, the 49ers' Super Bowl chances are nil. That's how important Smith is to this team.

There were three glaring areas of concern directly attributed to Justin's loss. The first is that Aldon Smith is not nearly as effective without Justin. In the past six quarters, it is no coincidence that Aldon has not registered a sack without Justin in there.

Aldon was neutralized by the Seattle offensive line and often double-teamed by a back or tight end on passing downs. He had only one solo tackle and five assists for the game.

The second issue is that replacement Ricky Jean-Francois proved that he is nowhere near the impact player that Justin is. Jean-Francois was repeatedly handled and unable to get disengaged from the man blocking him.

On Seattle's second play from scrimmage, Marshawn Lynch ran right through the hole created when tackle Russell Okung blew Jean-Francois off the line. The play resulted in a 24-yard touchdown run for Lynch, giving the Seahawks a 7-0 lead.

Jean-Francois was ineffective on both running plays and in rushing the passer. He was credited for no solo tackles. Seattle also did not need to use two men to block Jean-Francois. He was unable to beat one blocker and did not make a positive impact for the 49ers defense.

The final thing that was very noticeable if you watched Jean-Francois is the absence of hustle plays or "never-ending-motor plays" that we have come to expect from Justin. 

There were multiple occasions when the Seahawks occupied Jean-Francois for a while or ran the play away from his area. Jean-Francois stopped pursuing or just started watching, without giving chase. This absence of hustle comes from a lack of game conditioning. It bordered on just plain laziness.

Watching Jean-Francois being manhandled and unable to make any plays means the loss of Justin is that much more critical. Without a healthy Justin Smith, the 49ers can kiss this season goodbye.