NFL Network Insider Ian Rapoport initially reported the news on Searcy, citing confirmation from his agents.
"The #Titans have just released veteran S Da'Norris Searcy, according to @UniSportsMgmt. Another starting strong safety on the market," Rapoport tweeted.
Searcy was set to make $3.85 million in salary and bonuses next season. He signed a four-year, $23.75 million contract -- with $7 million guaranteed -- with the Titans in 2015.
The 29-year-old recorded 26 tackles and an interception while playing in all 16 games last season. He was limited to just six starts in 2017 after making 27 in his previous two seasons with the Titans.
Searcy has collected 330 tackles, 4.5 sacks and eight interceptions in 107 career contests with the Buffalo Bills and Titans. He was selected by the Bills in the fourth round of the 2011 NFL Draft.
Cassel has spent the past two seasons as a backup to Marcus Mariota. He completed 55 of 93 passes for 446 yards, three touchdowns and four interceptions in six career games with the Titans.
Weems had just one reception for five yards and returned two punts and two kickoffs this season.