Financial terms were not disclosed.
Kelly was released last month by the Oakland Raiders, where he spent the first nine seasons of his career.
Kelly was scheduled to make $6.5 million next season before the Raiders released him to clear up cap space. He had 45 total tackles, one sack and one fumble recovery last season, while starting all 16 games. His best years came in 2010 and ’11 when he recorded 14.5 sacks and six passes defensed in 32 games.