Thomas, 27, 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. The Bills signed him to their practice squad towards the end of last year before bringing him back on a future/reserve contract in January.
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.
Renfrow, 26, originally signed on with the Cardinals as an undrafted free agent out of back in 2014. Since then, Renfrow has had brief stints with the Packers and Seahawks before signing on with the 49ers in May of last year.
Unfortunately for him, he was among their final roster cuts at the start of the season, but later returned to the 49ers in October.
The Cowboys signed Renfrow to a future/reserve contract in January before waived him a few weeks ago.
Renfrow has yet to appear in an NFL game.