Keo, 27, is a former fifth round pick of the Texans back in 2011. He spent just over four years in Houston before he was waived at the start of the 2014 season.
The Bengals would later sign Keo to a future/reserve contract in January, but he was unfortunately among their final roster cuts coming out of the preseason.
Keo last appeared in an NFL game during the 2013 season. That year, he recorded 63 tackles, one interception, and six pass defenses for the Texans.