Chicago acquired the 40-year-old Timonen in a trade with Philadelphia in February, but he has struggled to come back after missing most of the season while recovering from blood clots discovered in his leg and lungs last summer. He had a minus-two rating in eight minutes of ice time in the Blackhawks' 5-4 overtime loss in Game 5 on Monday night.
The Ducks had a 3-2 series lead heading into Wednesday night's game at the United Center. Timonen has said he plans to retire after the season.
David Rundblad replaced Timonen in the lineup. It was his first appearance since Chicago's 4-1 loss in Game 1 against the Ducks.