To me, the pass rush can easily be addressed with Aldon coming back, Tank Carradine coming in, and more frequent blitzes with Bowman and Willis. The wide receiver situation can also be fixed with Manningham and Crabs coming back and the possible addition of a receiver via trade.
The thing that I am most concerned about at this point, is actually the run defense. MJD and the weak ass Jaguars had possibly their best game running the ball against us. Our run defense used to be dominant. Our line would never get pushed back. This has not been the case this year. Our run D has been suspect and I'm not sure why and I'm not sure how we can fix it. Mcdonald and Justin Smith just don't seem to be as stout against the run. Wish we could get that dominant Run D back, then our defense would be great again with the way our secondary has been playing.