Williams signed a one-year deal that could be pivotal to the Bears, who signed the former Denver Bronco despite his two past suspensions for violation of NFL rules on performance enhancing drugs.
Williams is also the heir apparent to Brian Urlacher, a perennial defensive star and fan favorite in the Windy City.
Sources said the new deal includes a base salary of $900,000 that is not guarantee just in case Williams again runs afoul of the league or the law. The deal also includes a series of bonuses that would boost its value up to $1.75 million.
Williams was due to make $6 million this season in Denver, which the Tribune said was the big reason he was cut by Denver. The Bears are banking on him regaining the form that made him the Broncos' leading tackler four out of five seasons prior to 2012.