McFadden got hurt again on Sunday. According to ESPN's Adam Schefter, McFadden "suffered a high ankle sprain on his first carry of the game, played through it before aggravating injury later. McFadden is scheduled to undergo an MRI on Monday and is considered week to week for now."
Judging by McFadden's renowned fragility, this will spell more carries for Jones. He will still share time with Mike Goodson in all likelihood though, and that won't do fantasy owners any good, especially in an offense that prefers to pass the ball. Goodson suffered an injury on Sunday as well, but he looked fine on the sidelines by the end of the game.
The Oakland Raiders are 30th in the NFL in rushing. Carson Palmer has thrown the ball over twice as much as McFadden has run it all season, and that margin is only going to get wider if McFadden is out of the lineup for any period of time.
On the season, Jones only has one carry for two yards. He hasn't found the end zone because he's been the third running back for most of the year. His limited experience doesn't bode well for making an immediate fantasy impact, regardless of Goodson's condition.
If he couldn't do that, why would he be the clear-cut starter even if McFadden is out?
You probably don't own Jones (at least I hope you don't), unless you play in an extremely deep league. Stashing him on the bench wouldn't have made any sense in the past few weeks, and it barely makes any more sense now.
If the Raiders are going to win games, it's going to come on defense and through the air. That doesn't leave room for the run game, and the offensive line doesn't block it well anyway.
Jones is a marginal talent who won't perform well in a pass-first system. McFadden wasn't running well, and he's twice the player Jones will ever be, even if he is hurt on a consistent basis.
Waiver-wire pickups are hard to come by at this point in the season. Picking up anyone who will earn starter's touches will be tempting, but don't take the bait here. Jones, even if he is listed on the depth chart as a starter, will still share a committee backfield with Goodson (assuming he actually is OK). More than 10 carries per back would be a stretch, and that doesn't translate to fantasy success.