David Johnson is going to miss extended time with a wrist injury; he's probably headed to injured reserve. It's a devastating blow to the Cardinals especially, and less importantly to fantasy teams that drafted Johnson at No. 1 or 2 overall. Both the team and those fantasy coaches need to find replacements fast.

The problem is there aren't a lot of backs that can do what Johnson can. The Cardinals don't have one, and it seems most likely that Johnson will be replaced by multiple players. Andre Ellington is one of them, and he says there's been no talk yet about how playing time will be distributed going forward.

“Once we know for sure, I have all the confidence (in other backs),” Bruce Arians said. “Andre was good, Kerwynn (Williams) looked good, our young guys, we will see what we’ve got. And we’ll see what’s out there.”

The Cardinals might bring back Chris Johnson, but he looked cooked in the preseason -- no way is he going to come in and have a heavy workload. The might add D.J. Foster off the Patriots practice squad, but he's also a smaller back; not cut out for a heavy-duty role.

Some leagues run waivers on Tuesday night (way too soon, by the way; should be Wednesday night at the earliest). What's the rush? But we have to deal with what we have.

If I had to rank the Arizona backs, I suppose they'd be Kerwynn Williams first and Andre Ellington second. Williams seems likeliest to be the main runner, Ellington the main pass catcher. That's where the skill set is.

But I suspect I'm going to be looking at other possible waiver pickups. Tarik Cohen in Chicago will likely be my top choice, and you can think about Marlon Mack (if available) as well.

If you had Johnson, best guess is that Williams is the guy to add, with Ellington an only slightly secondary choice. No doubt some will go after Chris Johnson or Foster, hoping to catch lightning in a bottle. But it's unlikely Arizona has or is able to find a back that can assume a Johnson-like role.

--Andy Richardson