McFadden hurt his foot in the first quarter against Kansas City two weeks ago. He did not practice at all during the bye week or this week. Coach Hue Jackson gave no timetable on his possible return.
"I know we're making progress each and every day," Jackson said. "I think he's getting closer and closer. To me, that mid-foot sprain, you just got to take it day to day."
Until McFadden is healthy, it will be Bush getting the bulk of the work for the Raiders. Bush's last start came in the season finale at Kansas City last season when he ran for 137 yards and a touchdown in an Oakland win.
"I have been in this situation for four years now," Bush said. "It's all the same. I just know when it's my turn to play I need to take care of my opportunities."
Bush rushed for 99 yards on 17 carries two weeks ago against the Chiefs and has 237 yards and three touchdowns on the season. He had 288 yards and three touchdowns in the three games McFadden missed last season with injuries, giving the Raiders confidence that the offense won't slow down without its biggest star.
Despite being limited to 4 yards on two carries against Kansas City, McFadden is still eighth in the league in rushing with 614 yards. He is averaging 5.4 yards per carry, has scored five touchdowns and is Oakland's second leading receiver with 19 catches for 154 yards.
Rookie running back Taiwan Jones has just seven touches on offense this season, rushing five times for 30 yards and catching two passes for 25. But he has similar game-breaking speed to McFadden and will likely serve as a change-of-pace option to the more physical Bush.
Jackson said it's time for Jones to step up and make the "special plays" the Raiders believe he can. Jones said he feels no added pressure to fill in for a player as heralded as McFadden.
"It's just football," Jones said. "I've been doing this my whole life, and I'm doing it every day in practice. It's just this time I might get to show everybody else what I can do."
For a complete look at all injuries around the league, go to NFL.com's injury page.
Copyright 2011 by The Associated Press