With the Arizona Cardinals' aerial attack, we know this much: Larry Fitzgerald is going to get his. The future Hall-of-Famer hasn't had fewer than 100 receptions in a season since 2014, and if there's anything we can say for certain about the Cardinals' passing game, it's that Fitz is going to see plenty of volume.

After that, things get a lot more cloudy. Receivers John Brown and Jaron Brown are both gone, running back David Johnson -- after sitting out all but one game in 2017 -- is back in the mix, and whether it's Sam Bradford or Josh Rosen at quarterback, there will be a new face of the offense after Carson Palmer's retirement.

The uncertainty around Arizona's wide receiver depth chart, especially with the potential downgrade at quarterback, seems to have people pretty low on the team's non-Hall of Fame wideouts. According to ESPN's live average draft position (ADP) results, Rookie Christian Kirk is being drafted as the 60th receiver off the board while holdover J.J. Nelson (110th) and former Dallas Cowboys receiver Brice Butler (125th) are basically going undrafted in most standard leagues.

With the receiving corps' low ADP across the board (outside of Fitzgerald), there's a solid chance that someone here ends up returning serious fantasy football value this season. And Butler is the best bet to be that one.

Targets Available

I open just about all of my articles looking at a player's potential volume, because without volume (or the potential for it), what are we doing here? Getting into efficiency is fine once you've established that the player stands to see significant work, but efficiency without volume is fool's gold.

Now, a guy with only 133 targets over five NFL seasons isn't the kind of player we can usually project for big volume, but the rare situation Butler steps into this season is quite intriguing.

The pass-catching duo of John Brown and Jaron Brown and their combined 124 targets are gone from last season. And considering the team's 592 total targets in 2017, that's good for a healthy 20.9% market share. So, a fifth of the Cardinals' targets are up for grabs, and that volume has to go somewhere.

There's the potential that a wideout doesn't benefit as much, as David Johnson could absorb gobs of volume from his spot in the backfield. Before his one-game season a year ago, the versatile back was second on the team in targets (120) in 2016.

Cardinals running backs combined for 130 targets in 2017, though, and even if you want to count some of Andre Ellington's workload as wide receiver targets, Week 3 and Week 4 saw him record 22 of his 50 targets, and he got significant running back snaps in both of those games. If we count just those 22 toward the running back total, Cardinals backs accounted for 17.2% of the team's targets, which is not far off the 18.9% that Johnson accounted for in 2016. Johnson returning to that elite 2016 workload still wouldn't do much to cut into the void left by the wideout departures.

Competition

What about the arrival of second-round pick Christian Kirk, who the fantasy-playing public have as the favorite to be the team's second wideout?

Since 2011, 28 wideouts have been selected in the second round of the NFL draft, and while that's some significant draft capital to spend on a player, teams haven't generally leaned on them too heavily during their rookie seasons. Only 1 of the 28 (Greg Little) saw at least 20% of their team's targets, while the average for the group is a fairly small 11.8% share. The median isn't much better, either, at 12.5%.

That isn't a knock on Kirk's potential as an NFL player or even his chances to have some impact as a rookie (an 11.8% market share would have been good for a shade fewer than 70 targets in Arizona last season). But it's to say that it's unlikely he steps in and fills the void in the offense.

But what indication do we have that Butler, who has never surpassed 35 targets in a season, can step up and be that guy?

Butler's Efficiency

At numberFire, we have a Dallas Cowboys from 2015 to 2017, and the Oakland Raiders in 2013 and 2014).

Efficiency numbers are hugely prone to variance, hence the fluctuation, and Butler's lack of volume makes these single-season samples fairly small. But two things really stand out here. That's a big positive differential over that five-year sample (producing at a clip slightly more than 24% higher than his teammates), and he's coming off by far the most efficient season of his career -- both in terms of his own numbers and differential between he and his teammates.

There's no guarantee that Butler can sustain this efficiency in an expanded workload, but a significant difference like that is, at the very least, an indicator that there's a lot of value in giving him the chance to contribute if you're the Cardinals.

Converting Workload to Production

If you're curious about whether that edge in NEP has translated to fantasy production, here's a look at the same discrepancy through the lens of fantasy points per target.

As you can see, it has.

Like with the real-world efficiency, we have seen Butler do it over a sizable stretch but never with a big one-season sample. That creates some room for concern, for sure, but at his price tag (basically free), you can afford the risk.

But in fantasy, it's not how well he does relative to his teammates that we're concerned about. If the offense is terrible, then even having an edge over his team wouldn't guarantee production. That makes the Arizona quarterback situation something we need to look into.

Wide receivers being targeted by Bradford, over the course of his entire NFL career, have averaged 1.52 fantasy points per target. Things are a bit less promising if we see Rosen at the helm, as wideouts have averaged 1.47 fantasy points per target from first-round rookie quarterbacks over the past five years. But again, that's not far enough off to be of any significant concern.

Moving Forward

We're obviously dealing with small single-season sample sizes for Butler, so it's hard to make any set-in-stone claim, but what we have is a reason to be optimistic.

Projecting efficiency is such an imprecise practice that the value doesn't really come from trying to nail it down to a specific number but rather from the general trends. Producing efficiently is a good sign, and being more efficient than your teammates is a good sign. But what this will come down to, ultimately, is opportunity. If Butler can become the Cardinals' number-two wideout, he'll return value at this price, even if the team's offense isn't great.

There is plenty of room for Butler to carve out a nice role for himself, and the fact that he's been productive when give the chance at the NFL level -- even if he hasn't had that one big year -- should give him a strong chance of doing just that. For a guy that is all but free in fantasy football drafts, the upside Butler offers makes him a terrific option as a late-round flier.