He was officially listed as a limited participant.
Bradford, who suffered a noncontact injury to his left knee during a Week 1 win over the New Orleans Saints, last practiced on Sept. 21 before seeking a second opinion from orthopedic specialist Dr. James Andrews.
Tests revealed there is no structural damage in the knee, thus not requiring surgery. Coach Mike Zimmer said the issue Bradford is dealing with is related to pain management.
"That's pretty much what it is, but I'm hoping it's not throughout the season," Zimmer said.
Bradford suffered a torn ACL in his left knee during a preseason game in August 2014 while a member of the Rams. He suffered the same injury in October 2013.
Because their upcoming game against the Chicago Bears is on Monday Night Football, the Vikings are running a day behind, thus operating Thursday on Wednesday's schedule. The starting quarterback typically addresses the media on Wednesdays, which is what Case Keenum did last week when Bradford was given time off to rest.
Keenum spoke to the media in the locker room Thursday morning. He started the past three games for the Vikings (2-2).
Zimmer would not name a starter for Monday's game but said Bradford will play if he's feeling better.
"If he's ready to play, he'll play," Zimmer said.