At certain points this week Lito Sheppard, Joselio Hanson, and Brian Dawkins all missed practice. That combination of players missing would make for a pretty thin secondary going into a big game... but the good news is that on Friday all three guys were full participants in practice and will play.
Also limited in practice this week was Brian Westbrook, who also returned for a full practice Friday and wil play. I wouldn't expect Westbrook to do all that much practicing the rest of the year.
Actually, the Eagles are remarkably healthy overall. They may well be the healthiest they've been all year. The only guy that won't play this weekend is Shawn Andrews, who hasn't played since week 2. This week Andy Reid said that they planned on leaving Andrews in California, where he had his surgery, for another week and then he should be able to get on a plane to come back. At that point, they'll evaluate where he is in his recovery.