The Cardinals added a special team upgrade to the roster on Monday -- and perhaps some depth on defense -- by signing cornerback Kris Boyd.

Boyd, a seventh-round pick of the Vikings in 2019, has played some defense -- 197 snaps the past two seasons -- but his focus was in special teams, for which he played 648 total snaps. He does not have an interception in his career but he has four fumble recoveries in regular-season play.

Boyd is the sixth cornerback on the roster. Marco Wilson, Antonio Hamilton, Christian Matthew, Rashad Fenton and Nate Hairston are the others fighting for their place on the depth chart, and the position figures to be heavily considered in the draft.

Cardinals defensive assistants Nick Rallis, Rob Rodriguez and Sam Siefkes all were on the Vikings' staff for part of the time when Boyd was in Minnesota.

The Cardinals officially open their offseason program on Tuesday with the voluntary Phase One strength and conditioning work.