Variety is the spice of the Cardinals' running back search

TEMPE, Ariz. -- Leading up to the start of free agency on March 9, we’ll evaluate the free-agency situation at every position for the Arizona Cardinals. We’ll look at who will return to Arizona in 2017, who’s set to hit the open market, what the Cardinals need at each position, and we'll throw out a few potential options to fill those open roster spots.

Position: Running back

Under contract: David Johnson, Kerwynn Williams

Pending free agents: Chris Johnson, Andre Ellington, Stepfan Taylor

What’s needed: In one word: depth. The Cardinals could lose three of their five running backs -- three of the four who back up David Johnson. Each of the three potential free agents -- Johnson, Ellington and Taylor -- had a distinct role. Chris Johnson, before he got hurt, was a between-the-tackles runner who had the vision, quickness and toughness to pick up yards. The Cardinals need a back who can pick up the slack if David Johnson is either having an off game or being contained, and that’s what Chris Johnson provided. Arizona will also need a running back whose athleticism shines to replace Ellington, as well as someone who can line up in the slot, take a swing pass and accelerate away from defenders. Finding a running back with top-notch speed will be among the Cards’ needs as well. The Cardinals also will be in search of a bruising back whom they could use on third down as a pass blocker or to get a tough yard or 2 if David Johnson isn’t available.

Possible fits: Joique Bell (Detroit Lions), Christine Michael (Green Bay Packers), Reggie Bush (Buffalo Bills)