Last week, Thomas declined to comment on being attacked. Thomas asked a reporter to call his attorney instead.
The FBI put Thomas in a hotel room for his protection for about a week after the assault because he is a witness in the gambling case, sources told The Oklahoman.
A federal grand jury this month indicted Mitchell, two of his sons, six other men and a Costa Rican company.
Mitchell, 57, is accused in the 81-count indictment of being the leader of an illegal gambling organization that had proceeds of at least $8.1 million.
Mitchell both hosted illegal high-stakes poker games at his Oklahoma City home and illegally took bets from across the country on sporting events, according to the indictment. He eventually sent clients to a sports betting Internet site run by the Costa Rican company, according to the indictment.
Thomas played poker at Mitchell's home, sources said.
Mitchell's attorney, Scott Adams, said last week, “What Teddy did was all legal. Everything he did was legal. ... They're misrepresenting what's going on. ... He was a professional gambler.”
About the attack on Thomas, Adams said, “Obviously, Teddy had nothing to do with it.”
Adams said Thomas owes money to “everybody in town.” Adams suggested somebody upset over a debt was behind the attack.
Thomas filed a bankruptcy petition last November, listing almost $330,000 in liabilities. He asked a bankruptcy judge to allow him to make monthly payments over five years to take care of his debts.
The bankruptcy judge in April rejected his payment plan and dismissed the bankruptcy case.
In a 2011 lawsuit, Mitchell accused Thomas of failing to pay off a $20,000 loan. Thomas denied owing the money. The case is pending.