If Andre Ellington Is Sidelined, Should You Trust Jonathan Dwyer in Fantasy Football?

After Eddie Lacy’s concussion in last night's season opener, the last thing fantasy football owners wanted was another running back injury. But today, that’s exactly what we all got.

Andre Ellington aggravated his left foot in practice on Thursday, and reports are ranging from “he could be out for an extended period of time” to “he still has a chance to play in Week 1.”

I’m not even close to a doctor, so I won’t speculate how big or small this foot injury is. I do analyze fantasy football though, and Andre Ellington being sidelined for any sort of time is a big deal. So let’s look at what that means.

Dwyer's Time

There’s plenty of optimism surrounding Ellington as we enter the 2014 season. Because of his big-play ability, he ranked eighth among the 47 100-plus attempt running backs last year in terms of Rushing Net Expected Points (NEP) per rush, doing so as a rookie. The passing game in Arizona improved dramatically over the second half of the season as well, providing hope for 2014.

Behind Ellington on the depth chart sits Jonathan Dwyer (imagine that, an ex-Steeler on the Cardinals roster) and Stepfan Taylor. Here’s a snapshot of their career Rushing NEP per tote numbers, alongside Ellington’s.

The sample size for these three runners isn’t large, mostly because Taylor and Ellington have played just a single season in the NFL, and Dwyer was usually a backup while in Pittsburgh. Overall, however, Ellington’s been the superior runner when you look at our Net Expected Points metric on a per touch basis.

A big thing to look at here, however, is Success Rate. What Success Rate measures is the number of rushes that contribute positively towards a player’s NEP. In this case, his Rushing NEP.

Andre Ellington’s Success Rate wasn’t strong last year, despite such a favorable per rush NEP score. Why? Because he’s a big-play guy, and often times wasn’t making positive plays for his team. In fact, among the same group of 47 runners referenced earlier, Ellington’s Success Rate ranked 30th, or 22 spots below his Rushing NEP per rush rank.

Stepfan Taylor is more of a grinder, as shown by his low efficiency but relatively high Success Rate. He’s got a 216-pound build, and compares physically to a player like Mark Ingram. It'd be interesting to see him play with some more volume, but if Ellington is indeed out, the team will more than likely give the majority of touches to Jonathan Dwyer, the man second on their depth chart.

Though Dwyer’s metrics look horrendous – and they are – a key point to make is that the Steelers offensive line was borderline atrocious during his time in Pittsburgh. When he received significant carries in 2012 and 2013 (156 and 49, respectively), Dwyer outperformed every Pittsburgh running back on a per touch basis outside of Le’Veon Bell. Given his low per-touch Rushing NEP score, it just goes to show how poorly the Steelers have run the ball over the last couple of seasons.

Dwyer hasn’t been horribly inefficient through the air, either. In terms of Reception NEP per target, which measures the number of points added on all catches divided by the number of targets a player sees, Dwyer’s efficiency is right around the league’s average.

The important thing here is that, while Jonathan Dwyer isn't a special talent, Stepfan Taylor may not be, either. And given his experience both in the NFL and under Bruce Arians, who once coordinator the Steeler offense, Dwyer should be the guy to add if you're looking for someone to replace Ellington in your lineup.

In Week 1, Arizona faces a San Diego rush defense that ranked 31st according to our metrics last year. If we hear that Ellington is out prior to Sunday lineups being locked - remember, Arizona plays on Monday night - playing Dwyer wouldn't be the worst move in the world given potential volume. If you're in a shallow league, however, you really should have better options.