Tillman sustained the injury in the third quarter of the Bears' 28-20 victory over the San Francisco 49ers on Sunday night.
Tillman released a statement Monday, saying he will be staying around Halas Hall and his role will "transition to helping coach and support (his) teammates."
Tillman tore a triceps muscle in the same arm last November and missed the last eight games of the 2014 season. The Bears used the short-term IR designation on Tillman last season for the injury.
Tillman leads the NFL with 42 forced fumbles since 2003.
I know this isn't the news we all wanted to hear but as they say, stuff happens. I'm truly blessed to have so much support from you all. — Charles Tillman (@peanuttillman) September 15, 2014
- Sarah Barshop