After four weeks of play, it seems as though the last thing the Arizona Cardinals need in their quest to climb back into the NFC West Division race is injury news.
However, when the organization placed safety Tyvon Branch on the team's injured reserve list Tuesday with a groin injury, the team embraced a decision it won't be able away from in the near future.
That decision? To finally expand the role of Tyrann Mathieu.
To date, Branch has been one of Arizona's steadiest defensive players, holding down the team's slot cornerback role in its oft-used nickel package and recording 23 tackles and two passes defended through four games. Though it's no fault of his own, Branch is no Mathieu, and it's time for the Cardinals to turn the corner.
Over the past three seasons, Mathieu has earned a living not as a traditional safety, but as a play-making nickel cornerback with an ability to shut down receivers from the line of scrimmage through the play and serve as an added presence against the run. While Branch has been serviceable against the pass, save for a handful of reps against New England in week one, he has also failed to make much of an impact against opposing rushing attacks.
Arizona defensive coordinator James Bettcher uses his nickel package more frequently than nearly any other defensive coordinator in the league, but many analysts believed that without a completely healthy Mathieu, Bettcher might shy away from his nickel package at the start of this season.
Mathieu is still recovering from a torn ACL suffered last December, and has yet to demonstrate he's feeling 100 percent healthy. As such, Arizona has kept him out of the most demanding, complex position within its defensive structure at nickel cornerback, and used him in the traditional role of a high safety responsible for a deep zone in coverage.
Even with Mathieu's role limited, though, Bettcher hasn't reduced Arizona's nickel package dependence, and the Cardinals have suffered as a result. The team hasn't been nearly as effective at stopping the run this season, and despite Branch's competence as a nickel corner, it has lacked a truly dynamic playmaker in Mathieu on the perimeter.
Though he's just 5-foot-9 and 186 pounds, Mathieu has developed a reputation as an unstoppable force in the open field, a rarity for a defensive back, and his presence alone made the Cardinals' defense truly special last season. With Mathieu on the field in 2015, Arizona went 12-2 and hardly allowed opposing offenses' breathing room. With Mathieu off the field, the Cardinals went 2-2 including a devastating 49-15 loss to Carolina in an NFC Championship game in which its secondary was torched.
Taking two thirds of his snaps in the slot corner role, Mathieu notched an eye-opening 17 passes defended and five interceptions that made him a candidate for the NFL's Defensive Player of the Year. Though he's played in all four games this season, it's clear Mathieu isn't the same player as a high safety as he is in the slot, and Arizona's defense has suffered as a result.
The Cardinals signed Branch to a two-year, $8 million deal this offseason as insurance for Mathieu. Arizona knew Branch could play in the slot, and it knew if he could assimilate himself into the team's nickel package, that it could start the year with Mathieu on the field in an easier-to-handle role.
Arizona received what it needed out of Branch, but at some point, the Cardinals were going to have to make a change. Whether that change would have come this week or later on this season is uncertain, but Branch's injury forces the Cardinals' hand.
At this point, Arizona has no other dependable defensive back to play at nickel corner, so it's go-time for Mathieu. At 1-3, the Cardinals have little time to waste to determine if their biggest defensive star is ready to handle the load in the slot, but they're about to find out.