Mitchell (undisclosed) reached an injury settlement with the 49ers on Wednesday, Aaron Wilson of KPRC 2 Houston reports.
The Titans placed Mitchell (hamstring) on injured reserve Thursday, Jim Wyatt of the team's official site reports.
Mitchell (hamstring) has been ruled out for the remainder of Sunday's game against the Chargers, John Glennon of SI.com reports.
Mitchell recorded eight tackles (seven solo), three pass defenses and one interception during Sunday's 17-10 win over the Broncos.
The Titans signed Mitchell to the practice squad Wednesday, Jim Wyatt of the team's official site reports.
The Patriots released Mitchell on Tuesday, Mike Reiss of ESPN.com reports.
Mitchell and the Patriots agreed to terms on a one-year, $3 million contract Wednesday, Adam Schefter of ESPN reports.
The Texans are releasing Mitchell on Thursday, Cole Thompson of SI.com reports.
Mitchell (undisclosed) is no longer on the Texans' injury report Friday.
Mitchell (undisclosed) is inactive Sunday against the Chargers, Brooks Kubena of the Houston Chronicle reports.