Yes, DuBose has a lot of catching up to do, so it's a good guess that he might end up on the practice squad this year. If he can show some special teams talent, he might make the roster by the end of the year, given injuries and all.
I'm glad the Packers are careful with injuries - what's the point in hurrying Gary or Stokes back? I do feel badly for the young guys like Cotton, not even drafted and only a slim shot anyway, and then he's hurt. Even if say a fifth round pick gets hurt, he's likely to get more consideration and rope than an undrafted guy. They probably fight like hell to get on the field, no matter how hurt they are.