Several local commentators have been carrying on about how the def backs haven't shown much in preseason and worry about how they'll fare against top receivers in the league.
IMHO the DBs have been doing a decent job for the first few seconds on plays then it breaks down. Why? It's part scheme and it's partly because there is no pass rush on most plays.
If you look closely it's not all on the backs; the line isn't getting it done up front and is giving the qb time to throw.