Cardinals RBs' room coming into focus

TEMPE, Ariz. -- On the balance sheet, the Arizona Cardinals are even when it comes to running backs.

They lost two this offseason when they didn't re-sign either unrestricted free agent Rashard Mendenhall or restricted free agent Alfonso Smith. But they gained two, signing Jonathan Dwyer last week and Robert Hughes to a futures contract.

The two they lost were better than the two they gained, although it's ironic that Dwyer is replacing Mendenhall for the second time in their careers. Dwyer filled in for Mendenhall when the latter tore his ACL at the end of the 2011 season with the Pittsburgh Steelers.

With Arizona's decision Tuesday to not re-sign Smith, it means that Dwyer will have more of a role on third down. But it also means that, as of Tuesday, Ryan Williams will have a chance to make the roster.

That can easily change if the Cardinals pick up a running back or two throughout free agency and the draft, but as the third or fourth best back in the room, Williams' future with the Cards is looking bright. But, as I said, that's as of today.

If Williams hadn't reinjured his knew last training camp, it's unlikely Smith would've been on the roster. He struggled to pick up the offense despite having a strong preseason.

It's clear that head coach Bruce Arians wants to ride out Andre Ellington as his primary rusher with Stepfan Taylor as the second option. From there, however, the third and fourth backs are still to be decided. It's likely Dwyer will enter training camp with the upper hand because of his relationship with Arians.

But depending on who the Cardinals draft or if they sign anyone else, the four main backs on the roster -- Ellington, Taylor, Dwyer and Williams -- may be the four you'll watch during the season.