Too many injuries from the start I think is the problem.
In the beginning of the year, the lack of running game (Grant) and the O-Line looking like one of those pourous cheeseheads, contributed to losing games.
Now take the injuries on defense. Harris missed games, Bigby, now Barnett, d-line took its hits, and KGB was cut. Now there is not enough depth on the d line. What needs to be done via draft is the remodeling of the d line. With the first 3 picks, go d line, o line d line. This years draft is very strong on the line. Take advantage of that.
Then with the fourth, snag a solid safety. The continue to build o line depth with the next and then maybe get some backup linebackers. I really think that could be a solid start for them.
Also, for TT, don't get questionable guys who will be serious hits or busts, like Harrel. Go for the sure fire guy who might not be as stellar as the one in front of him but more likely to succeed in the NFL.
The team does not need to be rebuilt, just remodeled. Dump Pickett or keep him situational, cut Harrel, and bolster up that line through the draft and a free agent or two while the picks develop.