Dowling, 23, was the Raiders seventh-round pick back in May of last year out of Western Kentucky. His rookie season was cut short after he was placed on season-ending injured reserve in December.
The Raiders ultimately elected to cut him loose back in late August, but he later caught on with the Dolphins at the start of the season. Since then, he’s been on and off of the team’s practice squad.
In 2014, Dowling appearing in seven games and recording four tackles while playing a total of 13 snaps, according Pro Football Focus.
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, and Browns, but has yet to receive an offer from either 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.