The Browns, Steelers and Colts worked out Bentley in recent weeks, but he was not offered a contract by any of the teams.
Bentley, 26, is a former third-round pick of the Lions back in 2012. He had one year remaining on his four-year, $2.649 million rookie contract when Detroit elected to cut him loose back in June.
In 2014, Bentley was limited to appearing just two games after he sustained a season-ending ACL injury in earlier September.
During the 2013 season, Bentley appeared in 13 games for the Lions and recorded 29 tackles and five pass defenses. Pro Football Focus had him rated as the No. 82 cornerback out of 110 qualifying players that year.