We started out discussion of 49ers-Seahawks matchups yesterday.  Some of today's discussion centers on matchups that have been affected by injury, be it significant or otherwise.  You never want to get too confident, but when you're facing a team that has been decimated by injury, your chances have to improve (assuming you can take advantage of the weaknesses).

Match-Up #4: 49ers Pass Rush vs. Seahawks pass protection
Advantage: 49ers - In accumulating three combined sacks, Parys Haralson and Justin Smith spent a good chunk of time taking on the right side of the Cardinals offensive line.  Seattle recently placed right guard Rob Sims on injured reserve with a torn pectoral muscle.  In the first half of the Cardinals game the 49ers established a very solid pass rush.  The Cardinals brought in additional protection in the second half and stunted the rush and the 49ers couldn't make any adjustments.

The lack of wide receiver depth could be important in the developing pass rush.  If the 49ers can go straight man-to-man on the outside, that frees up a guy like Michael Lewis or a nickel back to add to the pass rush.  The 49ers are also thin at running back, so one would hope the 49ers try and tire them out with repeated blitzes.

Match-Up #5: Seahawks Passing Game vs. 49ers secondary
Advantage: 49ers - Matt Hasselbeck is still a very solid quarterback.  He's getting a little old, but given sufficient protection, he can pick apart defenses.  However, I can't imagine many quarterbacks who could make big plays with all unproven receivers.  This is probably the biggest story of the week considering the sheer volume of injury. 

Last weekend the 49ers secondary gave too much of a cushion due to fears of being beaten deep.  It's entirely possible Courtney Taylor or Jordan Kent could absolutely destroy the 49ers secondary.  However, it's not something the 49ers should play for at the beginning of the game.  The 49ers top 4 corners (Clements, Harris, Spencer, Strickland) is not the best group in the league, but I'd bet they're one of the better collections of talent.  They're paying these guys to shut down the pass game and this is the perfect opportunity for them to make a big impact on the overall defense.

Match-Up #6: Seahawks return game vs. 49ers return coverage
Advantage: 49ers - The injuries have even impacted the return game.  Nate Burleson was the primary return man for the Seahawks, averaging 18 yards per punt return against Buffalo (with a long of 21 yards).  The 49ers dealt with a serious averaging starting field position issue, although that was due to turnovers.  However, anything that will potentially hurt Seattle's field position is a good thing. 

The 49ers did a very good job the few times Arizona returned the ball and will look to continue this week.  The preseason was a disaster at times on special teams but so far that hasn't carried over to the regular season.  I realize it was mostly due to turnovers, but if the 49ers can avoid giving Seattle phenomenal field position, the defense might not have to exert themselves quite so much.