Updated

EDEN PRAIRIE, Minn. -- Minnesota Vikings quarterback Sam Bradford's left knee has so far responded well to two weeks of rest, raising the possibility of a return for the next game at Chicago.

Bradford said Friday he is "definitely feeling better" after practicing with the team on a limited basis Thursday. That was his first work on the field in two weeks. He has missed the last three games because of soreness and swelling from an injury that occurred in the season opener.

Bradford declined to divulge the specific diagnosis, but said he's experiencing a residual effect of ACL surgeries he had in 2013 and 2014. Case Keenum has filled in, while the Vikings have lost two of three. They play Monday against the Bears.