No mention of Isheem Young in the defensive backfield? I'm not worried about that position.
I can't say I'm "worried" about any position this year. I'm "interested" to see how our lines look but confident we'll be okay. Heacock has a history of turning out productive units, and the progress of the OL over the last season has me as optimistic as I've really ever been.
WR is a bit of a question mark. Can they get separation and read the zones to find the soft spots? But I anticipate Brock will have better protection this year to get good balls to the right person.
Special teams, specifically the coverage units, is the only real concern IMO. People like to rag on our FG kicking, but we've actually been pretty average lately. Being above average would be a bonus. Not having to attempt 40+ yard FGs would do a lot for our (or anyone's) average.