When McFadden's most recent injury knocked him out of the November 3rd loss to the Philadelphia Eagles and kept him out for the following three weeks, Jennings took a firm hold of the starting job.
In his five games as the feature back, he has carried the ball 90 times for 448 yards, giving him an average of just under five yards per carry.
Although this stretch has seen a number of disappointing losses for the Raiders as a team, including Thursday's blown lead in Dallas, Jennings has been the offense's most reliable and important player in that time.
So much so that when McFadden returned to the lineup against the Cowboys, Jennings still held on to the starting role, carrying the ball 17 times to McFadden's five.
Like several other key Raiders players, both backs will be free agents at the end of this season and are certain to garner interest from other teams on the open market.
As a result, the running back situation represents one of many key decisions general manager Reggie McKenzie will have to make when it comes time to spend the significant amount of salary-cap space the Raiders will benefit from.
The question is, do the Raiders make a long-term commitment to Jennings, McFadden or both?
If it becomes one or the other, that decision is made all the more difficult.
McFadden has been with the Raiders since being selected fourth overall in the 2008 draft, and although his durability has been questioned, he's as tough a runner as any back in the NFL.
Now in the right offensive/blocking scheme—and still a young player even by running back standards at 26—it may be too early to give up on him.
If his injury questions end up driving his free-agent price tag down, why would you? McFadden remains a player that demands a lot of defensive attention and can be used in a variety of ways to help the offense.
Jennings, whom the Raiders were able to bring in on a relatively inexpensive one-year deal due to a down season in Jacksonville, has certainly earned himself a significantly better contract.
His performance during the remainder of the season will likely determine just how much his price tag will continue to rise, but the Raiders will undoubtedly be interested in bringing him back either way.
Much of the debate this offseason will surround which player the Raiders should make an effort to keep, but why not both?
Again, remembering the increase in the team's salary-cap space taking effect in the new league year, the idea is not completely out of the question.
Despite the NFL's trend toward a passing game, depth at the running back position remains as important as that of any other when considering the physical toll these players incur.
For the most part, teams are now relying on a committee of running backs to get the job done and keep each other fresh instead of a lone feature back to center their offense around.
When healthy, the Raiders have quite the formidable duo in Jennings and McFadden—as well as the potential contributions sixth-round draft selection Latavius Murray could have when he returns from injury next season.
As always, the key will be remaining healthy, but the odds of the team finding a more talented group elsewhere on the free-agent market is relatively slim.
With so much salary-cap flexibility, the Raiders' first priority should be to retain the key pieces they already have and only then looking to upgrade elsewhere as needed.
Jennings' contributions this season have certainly made him a priority for the Raiders to re-sign for at least the next few years. Having said that, that doesn't diminish the value McFadden still has as an offensive playmaker.
Considering the talent Jennings and McFadden bring, the way they complement one another as runners and the value of running back depth in the NFL, the Raiders should look to get both backs in the fold once the upcoming offseason gets underway.
Moving forward, both their running game and offense as a whole will be much better for it.