The Ravens first team defense allowed 11 first downs and 184 yards to the Cowboys Saturday night. The run defense and pass rush weren't what you expect from the Ravens and the pass defense was subpar, but what would you expect when you're down your starting corners. Me? I'm not panicking. Jimmy Smith's' x-ray came back negative, Asa Jackson should be good next week, and Lardarius Webb could play next week, so that's a possible two out of three starting corners that can play on Saturday (whether they should play is a different question entirely). But all three of them should be ready Week 1.
The pass rush was underwhelming. However it's preseason and if there was a time to be vanilla in the area of pass rush, this would be it. If Dean Pees decided to use those new aggressive schemes that he and John Harbaugh said that he was developing that would be incredibly unwise.
The Ravens defense looked substandard against the Cowboys and that's a cause for concern, but the defense hasn't played a meaningful game yet. Therefore it's too early to worry.