The Chicago Sun-Times reports that Assistant State's Attorney Stephanie Gersch says Moffitt was found with a gram of cocaine, four ecstasy pills and 10 grams of marijuana early Sunday at The Underground.
Police reports say a man asked Moffitt about selling drugs at the nightclub and Moffitt allegedly hit him in the head.
Moffitt, 27, was released on his own recognizance. It's not clear whether he has an attorney in the case.
Moffitt, whose address is listed as being in Renton, Wash., also played for the Seattle Seahawks.
The guard quit the NFL in November, saying he had lost his love for the game and was tired of risking his health.