Williams, 24, is a former fifth-round pick of the Lions back in 2016. He was in the second year of his four-year, $2.544 million contract when Detroit waived coming out of the preseason.
In 2016, Williams appeared in 14 games for the Lions and recorded 26 tackles, no sacks and a fumble recovery.
Bradford, 25, is a former fourth-round pick of the Packers back in 2014. He managed to make the 53-man roster during his first year in the NFL before being converted to inside linebacker this last year.
Bradford spent the 2015 season on the Packers their practice squad and was unable to make the 53-man roster coming out of the preseason again this year. Green Bay waived Bradford back in December and he was later claimed off of waivers by the 49ers.
The 49ers re-signed him to a one-year exclusive rights contract this offseason before cutting him loose shortly after the draft. Bradford later signed on with the Bills but was waived coming out of the preseason.
In 2016, Bradford appeared in six games and recorded five tackle and no sacks for the Packers and 49ers.