Brock was signed on April 2 to a one-year contract. He started seven of the 10 games he was active for.
He finished his time in Arizona with 37 tackles, two pass breakups, one batted pass and one dropped interception.
Arizona also released Zach Zenner, who was inactive the last two games after signing with the Cardinals on Oct. 23. He had two catches for minus-3 yards and one catch for 13 yards with the Cardinals.
The Cardinals are 3-8-1 and host the Pittsburgh Steelers on Sunday.