In addition, rookie defensive end Shea McClellin also has been ruled out for Monday's game against the San Francisco 49ers.
The Bears didn't explain why the announcement was made today, before the team's second meaningful practice in preparation for the next game. The Bears will also practice Saturday before holding a walk-through Sunday in advance of their flight to the Bay Area.
Cutler suffered a concussion late in the second quarter of last Sunday's 13-6 loss to the Houston Texans. Linebacker Tim Dobbins drilled him, helmet-to-helmet, and he was flagged for unnecessary roughness. On Wednesday, the NFL also announced Dobbins was fined $30,000 for that hit.
"When a guy has a concussion, whether it's the first or whatever, it's a concern for you," Bears coach Lovie Smith said earlier this week. "He's not going to go back practicing until he's completely well and ready to go.
"He won't play until there's no issues with that."
Concussions have long been in the spotlight but it became an even bigger topic this week, when Cutler, 49ers quarterback Alex Smith and Philadelphia Eagles quarterback Michael Vick all suffered concussions. Vick was deemed to have a very serious concussion, but Smith was cleared and practiced on a limited basis Wednesday and Thursday.
On Sunday, before the Bears kicked off against the Texans, team CEO Ted Phillips, former players Otis Wilson and Gary Fencer, as well as other guests and experts participated in a forum to discuss concussion/ traumatic brain injury.
Soldiers from the United States Army were in attendance as part of the NFL's partnership with the U.S. Army to improve awareness of traumatic brain injury and further research.