Vasher, 27, originally hurt the thumb in a Week 4 win over the Philadelphia Eagles. Following surgery, he missed three games.
On the team's Web site Wednesday night, Coach Lovie Smith said Vasher will "be out for a while," but declined to speculate about whether the Bears will place the 2004 fourth-round draft pick, who is in his fifth NFL season, on injured reserve.
"Right now all I can say is he's out. He's not playing this week," Smith said. "Whenever you have a fracture and you re-injure the same hand that you had a little trouble with, I mean you can go from there, so right now just know that he's out now."
Vasher, who has been plagued by injuries the past two seasons, has 21 tackles and one interception this season.