This comes just a few days after 49ers LB Chris Borland announced his retirement from the NFL after just one year. San Francisco lost ILB Patrick Willis last week after he too decided to call it a career.
Thomas, 25, originally signed on with the Saints as an undrafted free agent out of Stanford. Since then, he’s played for the Raiders, Falcons and Packers before signing on with the 49ers in May of last year.
Thomas is under contract for the 2015 season and stands to a base salary of $510,000.
In 2014, he appeared in five games and recorded three tackles as a special teams player.