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.
Bear fans and Chicago, thank you for your words of encouragement and prayers...I really appreciate it. #BearDown— Charles Tillman (@peanuttillman) September 15, 2014
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