Butler, 27, is a former third-round pick of the Chargers back in 2010. He was entering the third year of his seven-year, $51.8 million contract when he was released in a move that freed up $2,590,000 in available cap space for the Chargers.
The Cardinals signed him to a contract a few months ago. However, he was later cut loose as the team trimmed their roster down to 53 players a few weeks ago.
In 2015, Butler appeared in all 16 games for the Chargers and recorded 43 tackles, a half sack, a forced fumble and a recovery.