Thomas, 26, is a former fourth-round pick of the Redskins back in 2013. He was waived by the Redskins a few months ago in a move that cleared $510,000 in cap space for Washington.
The Dolphins would later sign him to a contract, but he lasted just a few weeks in Miami before he was among their early roster cuts.
Since then, Thomas has worked out for the Raiders, Jets, Browns and Bills, but has yet to receive an offer from an a new team.
In 2014, Thomas appeared in eight games and recorded 27 tackles and fumble recovery. He previously missed the entire 2013 season after he sustained a broken foot.