Cardinals field 2nd-youngest secondary

TEMPE, Ariz. -- There’s a youth movement in the Arizona Cardinals secondary.

Cardinals free safety Tyrann Mathieu turned 22 on Tuesday, a few days after Arizona drafted 21-year-old strong safety Deone Bucannon. Both are projected to be starters, giving the Cards' starting safeties an average age of 21.5. Add in the cornerbacks, 23-year-old Patrick Peterson and 30-year-old Antonio Cromartie, and Arizona has the second-youngest projected starting secondary in the NFL.

The average age of the Cardinals’ starting defensive backs is 24. Only the St. Louis Rams have younger average starting secondary at 23.75 years. Arizona is also the only team that has three projected starters 23 or younger.

Arizona has used the draft to build the majority of the secondary. Mathieu and Bucannon were picked in the last two years, while Peterson was drafted in 2011. But like GM Steve Keim has said all along, he wants to use free agency as a way to complement the draft. That’s what he did with Cromartie, who was signed in March.

One of the backups at safety -- Rashad Johnson, 28 -- was drafted by the Cards. The primary backup at corner, Jerraud Powers, who is 26 but will have a birthday by time the season starts, was signed as a free agent in 2013. Backup safety Tony Jefferson, 22, was an undrafted free agent.

On the heels of St. Louis and Arizona, the NFC West has the youngest average secondaries in the league at 24.7 years.

The San Francisco 49ers have the ninth-youngest projected starting secondary at 25.25 years old while the Seahawks, anchored by Richard Sherman, 26, and Earl Thomas 25, were 15th.

If the Cardinals can keep Peterson, not only will the Cardinals have youth patrolling the defensive backfield for years to come but the West will be tough to pass against for the foreseeable future.