Johnson will be good, but he is not going to get after the quarterback. Solid against the run, and I imagine they're going to use him how they used Laboy last year. Only that he is a much better version of Laboy.
Still need some form of pass rush though. Phillips isn't getting younger, Barnes isn't THE answer.
I don't think they're expecting him to get after the passer. Him being a force in the run game should take the pressure off of guys like Barnes and Phillips making them better rushers IMHO.