So far, they haven't done much about it.
Porter has already played 250 defensive snaps in four games this season, according to ESPN Stats & Information. That works out to 62.5 snaps per game, making Porter pretty much an every-down player.
O'Brien Schofield, the outside linebacker Arizona hopes to groom as Porter's successor, has 63 snaps all season.
The basic problem: Porter has vast experience in the defensive system new coordinator Ray Horton brought from Pittsburgh, where Porter spent his first eight seasons.
Schofield, 24, has very little NFL experience of any kind. He was rehabbing a knee injury when the Cardinals drafted him, recovering in time to play the final 10 games last season. The lockout left him playing catchup once the Cardinals finally reported for training camp. With regular-season games on the line, the coaching staff must balance doing everything it can to win against getting needed work for a young player finding his way.
On the other hand, Seattle has found a starting role for rookie middle linebacker K.J. Wright, a fourth-round choice with 97 snaps in the three games he has played. San Francisco has found considerable playing time for rookie first-round pick Aldon Smith, who played a season-high 39 snaps in Week 4 and has played at least 20 every week.
"O’Brien is a young player and we are trying to get him to where he can play fast," Cardinals coach Ken Whisenhunt told reporters during the week. "That’s a process with young guys. You have to remember about O’Brien, he had eight weeks last year and no offseason. ... We are working to get the rotation right for all those guys so we can keep them where we can play at a high level."
The Cardinals' defense has been on the field extensively this season. Arizona, St. Louis and Indianapolis are the only teams with at least 65 plays on defense in every game this season, according to the NFL.
Porter has six sacks in 18 games with the Cardinals. He had 26.5 sacks in 30 games with the Miami Dolphins over the 2008 and 2009 seasons.
"We brought Joey in because we thought he had enough left, especially in certain situations to be able to rush the passer, and to give us some leadership," Whisenhunt said. "Things haven’t gone the way we wanted them to defensively. Joey is accountable. He understands what it takes to be successful. We’re going to continue to work to try to put him in the best situations and not overburden him by giving him too many snaps."