Can you trust a Cardinals running back?

After years of disappointing fantasy production, is there any reason to believe that an Arizona Cardinals running back can emerge as a legitimate fantasy threat?

Calling Beanie Wells' 2010 campaign a fantasy disappointment would be akin to calling Bernie Madoff a bad investor. Sure, both analogies begin to sketch the breadth of the subject matter, but the truth is that without further description, neither portrays a complete representation of the disaster that would unfurl upon their victims. Drafted as the 14th running back on average last season, Wells posted just 51 total fantasy points for the total season. To put that into perspective, last season's top fantasy running back, Arian Foster, scored 53 points in the first two weeks of the season. With that said, let's remember there were reasons Wells was drafted so early last season.

The most prominent reason for Wells' high draft position last season was that he was a solid fantasy producer during the last eight games of the 2009 regular season, when he racked up 626 total yards and six touchdowns. Fantasy owners seemed to ignore the plethora of injuries that affected Wells' production at Ohio State and perhaps focused solely on those eight games. The prospects of projecting those numbers over a full season and then adding a mythical growth factor because Wells would be in his second year drove his draft position up to a point where he could likely only return the value of the pick that was used to select him. While that may sound good in practice, you win fantasy football championships by selecting players who overperform their draft slot, not by taking those that produce a neutral or negative value.

While projecting a sample size to a larger body of work might be just as valid a method for predicting future performance as any other, the real risk in Wells' sample size was that it required him to stay healthy enough to maintain his 4.6 yards per carry. Wells suffered a meniscus injury during training camp that would cause him to miss the first two games of the 2010 season. It affected his performance later in the season when swelling became an issue. The injury became a big risk because it both limited his playing time and his production when he was in the lineup. The final result was an almost apocalyptic drop in yards per carry to just 3.4, which, when coupled with Wells' almost complete invisibility in the Cardinals' passing attack, made him one the larger busts of the 2010 season.

Fast forward to the 2011 NFL draft, when the Cardinals shocked many insiders by using the 34th overall selection on Virginia Tech running back Ryan Williams. After investing a first-round pick in Wells in the 2009 draft and having the relatively productive Tim Hightower under contract, the move to draft Williams didn't seem to make much sense. That is, until you really analyze how offenses that have been run by head coach Ken Whisenhunt have been most effective.

While the Cardinals have been a primarily two-back offense since 2008, one should realize that split of the carries between multiple backs may not be what Whisenhunt wanted, but rather him playing the hands that were dealt to him. Specifically, in 2008 it was Edgerrin James' lack of production that caused the incorporation of Tim Hightower into the offense. In 2009, rookie Wells sprained his ankle early in training camp, which kept him out of most of the preseason. And, as mentioned before, Wells was injured in 2010 in a manner that also made having one feature back impossible.

Before 2008, offenses were rather different under Whisenhunt. When you look at the three seasons that Whisenhunt served as the Pittsburgh Steelers offensive coordinator and the first season he functioned as the Cardinals' head coach, the primary running backs in his offensive schemes averaged almost 292 carries per year. To put that into perspective, only eight running backs achieved that height last season.

Which brings us back to Williams …

ESPN.com NFC West blogger Mike Sando wrote in his recent report from the Cardinals camp, "Williams looks like the better pure runner. Where Wells is more of a downhill runner with straight-line tendencies, Williams has shown he can cut effortlessly, even at high speed. One of Williams' coaches from Virginia Tech told the Cardinals he had never coached a more talented player." While Williams did show a tendency to suffer hamstring issues at Virginia Tech, with a better training regimen and more oversight, one should expect that these issues would be minimized now that he's in the NFL.

When presented with these facts, statistics and observations, you can probably come up with a couple of different scenarios for the Cardinals backfield:

1. The Cardinals continue to utilize a split backfield. In this scenario, Wells would likely be the first-down back, with Williams handling passing-down responsibilities. Both backs would serve as valuable third or fourth backs on most fantasy squads.

2. The Cardinals establish one playmaker as the primary ball handler. Under this scenario, the primary ball handler has to be Williams, as Wells' skill set does not include the prerequisite talent necessary to be an effective pass-catching back.

If you asked me to bet on how this plays out this season, I'd lean toward the Cardinals opening the season with Wells as the early-down back with Williams as the primary third-down back. However, I also expect that Williams will overtake Wells and become a feature back beginning in Week 9. With this in mind, I have no problem using an eighth- or ninth-round selection to ensure that I own Williams in almost every league.

Ken Daube is a fantasy football analyst for ESPN.com. His ESPN.com fan profile is available at: http://sportsnation.espn.com/KenD17.