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 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.
"He's another playmaker," fullback Marcel Reece said. "Everybody calls him the `big back,' and we kind of make fun of him, but Mike is a ridiculous playmaker for this team. He can do everything -- he can run between tackles, he can hit it outside and I think that everybody has seen that. And if you haven't, you're about to see it."
Bush has made only 10 starts in his career, but does better with more work, which he should get this week. Bush has averaged 6 yards per carry for his career after he has had 15 runs in a game, compared to 4.2 before that.
"You get a flow, you get the feel of things and learn how guys are playing certain things," he said. "But even if you're not getting a lot of carries and that hole opens up, you need to hit it. But any back, the more carries you get the better you are."
Bush will have to be good to make up for the absence of McFadden. 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.
McFadden has been at his best recently against the Broncos, rushing for 434 yards and scoring four touchdowns in his last three games against Denver. McFadden's 6.3-yard-per-carry average in his career against. the Broncos is the highest of any back since the merger, leaving big shoes for Bush to fill.
"He's in a tough spot," Jackson said. "He plays behind arguably, in my opinion, one of the best running backs in this league. But I think Bush is a really, really good player himself. It's good when you have two of them in case one can't go, you have one you can lean on. I think he's done some really good things this year. He has big-game capability. He knows how to play. You've seen it here during his career here, and if he has to play I feel very comfortable with him playing."
Jones has had only 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."
The Raiders should be getting a key member of the backfield back in the lineup Sunday with Reece expected to start for the first time since spraining an ankle against the Jets
Reece, a converted wide receiver, creates matchup problems for the opposition with his speed and ability to line up wide against linebackers. Reece had six catches for 43 yards and a touchdown in his first three games.
Placekicker Sebastian Janikowski is questionable with a left hamstring injury, linebacker Rolando McClain is questionable with a sprained left ankle, and safety Michael Huff is questionable with an injured right ankle.
Jackson said he will watch Janikowski kick Saturday before deciding whether to bring back Dave Rayner to take his place Sunday.