They'll bounce back.
KC is just bringing some good heat and being deceptive by bringing 8/9 in the box. That's the way defenses should play though, I like, good for Rivers to face. This will help him & the rest of SD down the road, they'll make adjustments.
The only thing that worries me right now is Shaun Phillips' injury. That's are best pass rusher. I personally think SD should switch to a 4-3 because of that guy, have him and Merriman as DEs and Williams & Castillo in the middle at DT. They'll tear it up better on defense if they did that IMO. Guys like Phillips & Merriman shouldn't be dropping back to stop the pass, they should be using their aggressive talents to rush the QB at all times.