Actually, the Raiders run mostly a 4-3 defense to accentuate guys like DT Sapp and now DE Burgess. They started out as a 3-4 last year, where they thought htey would capitalize on creating chaos with blitzes by Travian Smith, Tyler Brayton, and KGB's brother.But: (and this is a bit one): They couldn't stop anything, or get to the QB, and their DTs and DEs were not well suited ot the alignment, they switched back to the 4-3 mid stream.
Consequently, even with coordinator Ryan still around, they opened training camp practice 2005 and the first pre-season game (against SF) in the 4-3 and htey were looking decent. Of course, its only preseason
Bottom LIne: Tim Johnson is unlikely to see full time action this year unless they really commit back to the 3-4. I personally do not see it happening from what i read each morning in the local paper. Of course, they could very well run that defense in situations if they feel it generates a pass rush.