Since taking over for Tom Cable, Jackson hasn't let his players make excuses and he's not about to start doing it himself.
"Next man up," Jackson said. "Can't worry about it. (If) he's out, he's out. Next man up."
Johnson injured his hamstring early in last week's 34-24 win against New York and hasn't practiced this week. Backups Joe Porter and Chimdi Chekwa took turns replacing Johnson against the Jets until defensive coordinator Chuck Bresnahan opted to stay with Chekwa, a fourth-round draft pick this year.
Jackson declined Friday to say who would start at right cornerback in place of Johnson.
Jackson indicated that Huff has passed the requisite tests players must go through after suffering concussions, though he was unclear on whether Huff had suffered a setback or not.
"Once you pass a test, there's still other factors you have to pass that are outside of the test," Jackson said. "We'll just keep working through those."
The good news for Oakland is that its own high-powered offense may get a boost with the possible return of wide receiver Jacoby Ford. Ford, who has not played since the season-opener when he strained a hamstring, was limited in practice Friday and is questionable but said he expects to play.
Copyright 2011 by The Associated Press