Biggest problem with our run defense is that our depth isn't great. Golston gets run over a lot. Jenkins is solid enough, but he and Bowen can't be out there every defensive snap. Getting Carriker back would be huge in that regard.
Just in general we could use another complete player at the DE position. Of course, we'll be hard pressed to find one in the upcoming draft or FA. If a NT falls, I wouldn't mind taking one, not because I think we need a major upgrade at NT, but because Cofield would probably be better utilized on the outside, but that NT had better be really good. Otherwise, I'm not worrying about it until later in the draft.
ILB might have to be a priority too, if Robinson is injured and London is finally declining. Mauti could be interesting there, he'd be the kind of guy I'd be interested in in the late 3rd, 4th round range.