Johnson, 25, was jailed for 60 days after police found six unregistered firearms during a raid on his home in December, while he was on probation for a 2005 weapons offense. He was released after serving half of a 120-day sentence for good behavior on May 13.

The suspension might be reduced to six games if he stays out of trouble with the law; meets the NFL's requirements, including counseling; and doesn't participate in any team activities during the ban, the league said in a press release.

The suspension takes effect after Chicago's final preseason game Aug. 30 against Cleveland.

He is the third player suspended by Goodell for multiple games since April for their off-the-field actions. The commissioner introduced a new personal-conduct code then, with the support of players, owners and union leaders. Goodell can impose punishment "even where the conduct itself does not result in conviction of a crime," according to the new code.

The commissioner on April 10 suspended Tennessee Titans defensive back Pacman Jones for the entire 2007 season after Jones was arrested five times in about two years. Goodell also handed an eight-game suspension on the same day to Cincinnati Bengals receiver Chris Henry, who was arrested four times in a 14-month period.

Johnson, who had 26 tackles and 3 1/2 sacks during the 2006 regular season, needed permission from a Cook County, Illinois, judge to leave Illinois to play in the league's Super Bowl title game in Miami in February. The Bears lost to the Indianapolis Colts, 29-17.