Thomas filed a grievance against the Ravens after his contract was terminated in August, Aaron Wilson of the Houston Chronicle reports.
Thomas had an on-field confrontation with teammate Chuck Clark in August, and the Ravens cut him, citing "personal conduct that has adversely affected the Ravens." The guaranteed $10 million in Thomas' contract then became void, and it appears that's what the All-Pro safety is seeking in his grievance. Thomas came close to signing in Houston earlier this season, but he remains a free agent at this time.