In my opinion there are multiple strikes working against Poppinga.
1. As mentioned ineffective blitzer.
2. He has proven that coverage isn't a strength either.
3. Last year, in the transition of a 3-4 backer.. he gave away the edge to easily.. our first responsibility in most 3-4 schemes on a running play is to establish the edge and pinch the running into the interior backers.. the teeth.. pull some film.. he got pinned in too frequently IMO.
4. His engage point is too tall in my opinion and he is very stiff in the hips... which effects the above.. he is not fluid in his breaks or transition.. which IMO, has a great deal of impact on issue 1 and 2.
5. He has to bring a tangible to the table that lesser priced backers bring.. without a cap this season.. that is even more true. His salary is working against him.. Chillar might make the same amount of coin.. but Chillar is a more versatile player than Pop.
Poppinga's real value IMO, is on special teams.. and unless he is noticeably better than Obi or a couple of the developmental rookies brought in.. I think his time in GB has run its course.
"The oranges are dry; the apples are mealy; and the papayas... I don't know what's going on with the papayas!"