The Titans waived C Hroniss Grasu to make room for Brock.
Brock, 31, wound up signing on with the 49ers as an undrafted free agent out of Belhaven College back in 2010. He was in the final year of his five-year, $17.323 million contract and set to make a base salary of $3.1 million for the 2017 season when the 49ers cut him loose.
The Seahawks signed Brock to a one-year deal in 2017 before trading him to the Vikings for a seventh-round pick. Brock signed with the Broncos for the 2018 season and signed with the Cardinals on a one-year deal for 2019.
Arizona waived him on Monday.
In 2019, Brock appeared in 10 games for the Cardinals and recorded 37 total tackles, no interceptions and three pass defenses.