The move apparently is insurance in case left tackle Marcus McNeill continues his holdout. McNeill, outside linebacker Shawne Merriman and wide receiver Vincent Jackson are unhappy with their status as restricted free agents.
Thomas was a first-round draft pick of the Philadelphia Eagles in 1998. He went to the Pro Bowl after the 2001, '02 and '04 seasons. He played in five NFC championship games and one Super Bowl with the Eagles.
Thomas signed with Jacksonville last year and played in just eight games, starting one.